Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
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1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD: releng/10.1/sys/kern/kern_sig.c 270788 2014-08-29 08:38:34Z kib $"); 39 40 #include "opt_compat.h" 41 #include "opt_kdtrace.h" 42 #include "opt_ktrace.h" 43 #include "opt_core.h" 44 #include "opt_procdesc.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/signalvar.h> 49 #include <sys/vnode.h> 50 #include <sys/acct.h> 51 #include <sys/capability.h> 52 #include <sys/condvar.h> 53 #include <sys/event.h> 54 #include <sys/fcntl.h> 55 #include <sys/imgact.h> 56 #include <sys/kernel.h> 57 #include <sys/ktr.h> 58 #include <sys/ktrace.h> 59 #include <sys/lock.h> 60 #include <sys/malloc.h> 61 #include <sys/mutex.h> 62 #include <sys/refcount.h> 63 #include <sys/namei.h> 64 #include <sys/proc.h> 65 #include <sys/procdesc.h> 66 #include <sys/posix4.h> 67 #include <sys/pioctl.h> 68 #include <sys/racct.h> 69 #include <sys/resourcevar.h> 70 #include <sys/sdt.h> 71 #include <sys/sbuf.h> 72 #include <sys/sleepqueue.h> 73 #include <sys/smp.h> 74 #include <sys/stat.h> 75 #include <sys/sx.h> 76 #include <sys/syscallsubr.h> 77 #include <sys/sysctl.h> 78 #include <sys/sysent.h> 79 #include <sys/syslog.h> 80 #include <sys/sysproto.h> 81 #include <sys/timers.h> 82 #include <sys/unistd.h> 83 #include <sys/wait.h> 84 #include <vm/vm.h> 85 #include <vm/vm_extern.h> 86 #include <vm/uma.h> 87 88 #include <sys/jail.h> 89 90 #include <machine/cpu.h> 91 92 #include <security/audit/audit.h> 93 94 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 95 96 SDT_PROVIDER_DECLARE(proc); 97 SDT_PROBE_DEFINE3(proc, kernel, , signal__send, "struct thread *", 98 "struct proc *", "int"); 99 SDT_PROBE_DEFINE2(proc, kernel, , signal__clear, "int", 100 "ksiginfo_t *"); 101 SDT_PROBE_DEFINE3(proc, kernel, , signal__discard, 102 "struct thread *", "struct proc *", "int"); 103 104 static int coredump(struct thread *); 105 static int killpg1(struct thread *td, int sig, int pgid, int all, 106 ksiginfo_t *ksi); 107 static int issignal(struct thread *td); 108 static int sigprop(int sig); 109 static void tdsigwakeup(struct thread *, int, sig_t, int); 110 static void sig_suspend_threads(struct thread *, struct proc *, int); 111 static int filt_sigattach(struct knote *kn); 112 static void filt_sigdetach(struct knote *kn); 113 static int filt_signal(struct knote *kn, long hint); 114 static struct thread *sigtd(struct proc *p, int sig, int prop); 115 static void sigqueue_start(void); 116 117 static uma_zone_t ksiginfo_zone = NULL; 118 struct filterops sig_filtops = { 119 .f_isfd = 0, 120 .f_attach = filt_sigattach, 121 .f_detach = filt_sigdetach, 122 .f_event = filt_signal, 123 }; 124 125 static int kern_logsigexit = 1; 126 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 127 &kern_logsigexit, 0, 128 "Log processes quitting on abnormal signals to syslog(3)"); 129 130 static int kern_forcesigexit = 1; 131 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 132 &kern_forcesigexit, 0, "Force trap signal to be handled"); 133 134 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 135 "POSIX real time signal"); 136 137 static int max_pending_per_proc = 128; 138 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 139 &max_pending_per_proc, 0, "Max pending signals per proc"); 140 141 static int preallocate_siginfo = 1024; 142 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 144 &preallocate_siginfo, 0, "Preallocated signal memory size"); 145 146 static int signal_overflow = 0; 147 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 148 &signal_overflow, 0, "Number of signals overflew"); 149 150 static int signal_alloc_fail = 0; 151 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 152 &signal_alloc_fail, 0, "signals failed to be allocated"); 153 154 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 155 156 /* 157 * Policy -- Can ucred cr1 send SIGIO to process cr2? 158 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 159 * in the right situations. 160 */ 161 #define CANSIGIO(cr1, cr2) \ 162 ((cr1)->cr_uid == 0 || \ 163 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 164 (cr1)->cr_uid == (cr2)->cr_ruid || \ 165 (cr1)->cr_ruid == (cr2)->cr_uid || \ 166 (cr1)->cr_uid == (cr2)->cr_uid) 167 168 static int sugid_coredump; 169 TUNABLE_INT("kern.sugid_coredump", &sugid_coredump); 170 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 171 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 172 173 static int capmode_coredump; 174 TUNABLE_INT("kern.capmode_coredump", &capmode_coredump); 175 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RW, 176 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 177 178 static int do_coredump = 1; 179 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 180 &do_coredump, 0, "Enable/Disable coredumps"); 181 182 static int set_core_nodump_flag = 0; 183 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 184 0, "Enable setting the NODUMP flag on coredump files"); 185 186 /* 187 * Signal properties and actions. 188 * The array below categorizes the signals and their default actions 189 * according to the following properties: 190 */ 191 #define SA_KILL 0x01 /* terminates process by default */ 192 #define SA_CORE 0x02 /* ditto and coredumps */ 193 #define SA_STOP 0x04 /* suspend process */ 194 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 195 #define SA_IGNORE 0x10 /* ignore by default */ 196 #define SA_CONT 0x20 /* continue if suspended */ 197 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 198 199 static int sigproptbl[NSIG] = { 200 SA_KILL, /* SIGHUP */ 201 SA_KILL, /* SIGINT */ 202 SA_KILL|SA_CORE, /* SIGQUIT */ 203 SA_KILL|SA_CORE, /* SIGILL */ 204 SA_KILL|SA_CORE, /* SIGTRAP */ 205 SA_KILL|SA_CORE, /* SIGABRT */ 206 SA_KILL|SA_CORE, /* SIGEMT */ 207 SA_KILL|SA_CORE, /* SIGFPE */ 208 SA_KILL, /* SIGKILL */ 209 SA_KILL|SA_CORE, /* SIGBUS */ 210 SA_KILL|SA_CORE, /* SIGSEGV */ 211 SA_KILL|SA_CORE, /* SIGSYS */ 212 SA_KILL, /* SIGPIPE */ 213 SA_KILL, /* SIGALRM */ 214 SA_KILL, /* SIGTERM */ 215 SA_IGNORE, /* SIGURG */ 216 SA_STOP, /* SIGSTOP */ 217 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 218 SA_IGNORE|SA_CONT, /* SIGCONT */ 219 SA_IGNORE, /* SIGCHLD */ 220 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 221 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 222 SA_IGNORE, /* SIGIO */ 223 SA_KILL, /* SIGXCPU */ 224 SA_KILL, /* SIGXFSZ */ 225 SA_KILL, /* SIGVTALRM */ 226 SA_KILL, /* SIGPROF */ 227 SA_IGNORE, /* SIGWINCH */ 228 SA_IGNORE, /* SIGINFO */ 229 SA_KILL, /* SIGUSR1 */ 230 SA_KILL, /* SIGUSR2 */ 231 }; 232 233 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 234 235 static void 236 sigqueue_start(void) 237 { 238 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 239 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 240 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 241 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 242 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 243 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 244 } 245 246 ksiginfo_t * 247 ksiginfo_alloc(int wait) 248 { 249 int flags; 250 251 flags = M_ZERO; 252 if (! wait) 253 flags |= M_NOWAIT; 254 if (ksiginfo_zone != NULL) 255 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 256 return (NULL); 257 } 258 259 void 260 ksiginfo_free(ksiginfo_t *ksi) 261 { 262 uma_zfree(ksiginfo_zone, ksi); 263 } 264 265 static __inline int 266 ksiginfo_tryfree(ksiginfo_t *ksi) 267 { 268 if (!(ksi->ksi_flags & KSI_EXT)) { 269 uma_zfree(ksiginfo_zone, ksi); 270 return (1); 271 } 272 return (0); 273 } 274 275 void 276 sigqueue_init(sigqueue_t *list, struct proc *p) 277 { 278 SIGEMPTYSET(list->sq_signals); 279 SIGEMPTYSET(list->sq_kill); 280 TAILQ_INIT(&list->sq_list); 281 list->sq_proc = p; 282 list->sq_flags = SQ_INIT; 283 } 284 285 /* 286 * Get a signal's ksiginfo. 287 * Return: 288 * 0 - signal not found 289 * others - signal number 290 */ 291 static int 292 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 293 { 294 struct proc *p = sq->sq_proc; 295 struct ksiginfo *ksi, *next; 296 int count = 0; 297 298 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 299 300 if (!SIGISMEMBER(sq->sq_signals, signo)) 301 return (0); 302 303 if (SIGISMEMBER(sq->sq_kill, signo)) { 304 count++; 305 SIGDELSET(sq->sq_kill, signo); 306 } 307 308 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 309 if (ksi->ksi_signo == signo) { 310 if (count == 0) { 311 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 312 ksi->ksi_sigq = NULL; 313 ksiginfo_copy(ksi, si); 314 if (ksiginfo_tryfree(ksi) && p != NULL) 315 p->p_pendingcnt--; 316 } 317 if (++count > 1) 318 break; 319 } 320 } 321 322 if (count <= 1) 323 SIGDELSET(sq->sq_signals, signo); 324 si->ksi_signo = signo; 325 return (signo); 326 } 327 328 void 329 sigqueue_take(ksiginfo_t *ksi) 330 { 331 struct ksiginfo *kp; 332 struct proc *p; 333 sigqueue_t *sq; 334 335 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 336 return; 337 338 p = sq->sq_proc; 339 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 340 ksi->ksi_sigq = NULL; 341 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 342 p->p_pendingcnt--; 343 344 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 345 kp = TAILQ_NEXT(kp, ksi_link)) { 346 if (kp->ksi_signo == ksi->ksi_signo) 347 break; 348 } 349 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 350 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 351 } 352 353 static int 354 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 355 { 356 struct proc *p = sq->sq_proc; 357 struct ksiginfo *ksi; 358 int ret = 0; 359 360 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 361 362 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 363 SIGADDSET(sq->sq_kill, signo); 364 goto out_set_bit; 365 } 366 367 /* directly insert the ksi, don't copy it */ 368 if (si->ksi_flags & KSI_INS) { 369 if (si->ksi_flags & KSI_HEAD) 370 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 371 else 372 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 373 si->ksi_sigq = sq; 374 goto out_set_bit; 375 } 376 377 if (__predict_false(ksiginfo_zone == NULL)) { 378 SIGADDSET(sq->sq_kill, signo); 379 goto out_set_bit; 380 } 381 382 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 383 signal_overflow++; 384 ret = EAGAIN; 385 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 386 signal_alloc_fail++; 387 ret = EAGAIN; 388 } else { 389 if (p != NULL) 390 p->p_pendingcnt++; 391 ksiginfo_copy(si, ksi); 392 ksi->ksi_signo = signo; 393 if (si->ksi_flags & KSI_HEAD) 394 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 395 else 396 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 397 ksi->ksi_sigq = sq; 398 } 399 400 if ((si->ksi_flags & KSI_TRAP) != 0 || 401 (si->ksi_flags & KSI_SIGQ) == 0) { 402 if (ret != 0) 403 SIGADDSET(sq->sq_kill, signo); 404 ret = 0; 405 goto out_set_bit; 406 } 407 408 if (ret != 0) 409 return (ret); 410 411 out_set_bit: 412 SIGADDSET(sq->sq_signals, signo); 413 return (ret); 414 } 415 416 void 417 sigqueue_flush(sigqueue_t *sq) 418 { 419 struct proc *p = sq->sq_proc; 420 ksiginfo_t *ksi; 421 422 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 423 424 if (p != NULL) 425 PROC_LOCK_ASSERT(p, MA_OWNED); 426 427 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 428 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 429 ksi->ksi_sigq = NULL; 430 if (ksiginfo_tryfree(ksi) && p != NULL) 431 p->p_pendingcnt--; 432 } 433 434 SIGEMPTYSET(sq->sq_signals); 435 SIGEMPTYSET(sq->sq_kill); 436 } 437 438 static void 439 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 440 { 441 sigset_t tmp; 442 struct proc *p1, *p2; 443 ksiginfo_t *ksi, *next; 444 445 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 446 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 447 p1 = src->sq_proc; 448 p2 = dst->sq_proc; 449 /* Move siginfo to target list */ 450 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 451 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 452 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 453 if (p1 != NULL) 454 p1->p_pendingcnt--; 455 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 456 ksi->ksi_sigq = dst; 457 if (p2 != NULL) 458 p2->p_pendingcnt++; 459 } 460 } 461 462 /* Move pending bits to target list */ 463 tmp = src->sq_kill; 464 SIGSETAND(tmp, *set); 465 SIGSETOR(dst->sq_kill, tmp); 466 SIGSETNAND(src->sq_kill, tmp); 467 468 tmp = src->sq_signals; 469 SIGSETAND(tmp, *set); 470 SIGSETOR(dst->sq_signals, tmp); 471 SIGSETNAND(src->sq_signals, tmp); 472 } 473 474 #if 0 475 static void 476 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 477 { 478 sigset_t set; 479 480 SIGEMPTYSET(set); 481 SIGADDSET(set, signo); 482 sigqueue_move_set(src, dst, &set); 483 } 484 #endif 485 486 static void 487 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 488 { 489 struct proc *p = sq->sq_proc; 490 ksiginfo_t *ksi, *next; 491 492 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 493 494 /* Remove siginfo queue */ 495 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 496 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 497 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 498 ksi->ksi_sigq = NULL; 499 if (ksiginfo_tryfree(ksi) && p != NULL) 500 p->p_pendingcnt--; 501 } 502 } 503 SIGSETNAND(sq->sq_kill, *set); 504 SIGSETNAND(sq->sq_signals, *set); 505 } 506 507 void 508 sigqueue_delete(sigqueue_t *sq, int signo) 509 { 510 sigset_t set; 511 512 SIGEMPTYSET(set); 513 SIGADDSET(set, signo); 514 sigqueue_delete_set(sq, &set); 515 } 516 517 /* Remove a set of signals for a process */ 518 static void 519 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 520 { 521 sigqueue_t worklist; 522 struct thread *td0; 523 524 PROC_LOCK_ASSERT(p, MA_OWNED); 525 526 sigqueue_init(&worklist, NULL); 527 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 528 529 FOREACH_THREAD_IN_PROC(p, td0) 530 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 531 532 sigqueue_flush(&worklist); 533 } 534 535 void 536 sigqueue_delete_proc(struct proc *p, int signo) 537 { 538 sigset_t set; 539 540 SIGEMPTYSET(set); 541 SIGADDSET(set, signo); 542 sigqueue_delete_set_proc(p, &set); 543 } 544 545 static void 546 sigqueue_delete_stopmask_proc(struct proc *p) 547 { 548 sigset_t set; 549 550 SIGEMPTYSET(set); 551 SIGADDSET(set, SIGSTOP); 552 SIGADDSET(set, SIGTSTP); 553 SIGADDSET(set, SIGTTIN); 554 SIGADDSET(set, SIGTTOU); 555 sigqueue_delete_set_proc(p, &set); 556 } 557 558 /* 559 * Determine signal that should be delivered to thread td, the current 560 * thread, 0 if none. If there is a pending stop signal with default 561 * action, the process stops in issignal(). 562 */ 563 int 564 cursig(struct thread *td) 565 { 566 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 567 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 568 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 569 return (SIGPENDING(td) ? issignal(td) : 0); 570 } 571 572 /* 573 * Arrange for ast() to handle unmasked pending signals on return to user 574 * mode. This must be called whenever a signal is added to td_sigqueue or 575 * unmasked in td_sigmask. 576 */ 577 void 578 signotify(struct thread *td) 579 { 580 struct proc *p; 581 582 p = td->td_proc; 583 584 PROC_LOCK_ASSERT(p, MA_OWNED); 585 586 if (SIGPENDING(td)) { 587 thread_lock(td); 588 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 589 thread_unlock(td); 590 } 591 } 592 593 int 594 sigonstack(size_t sp) 595 { 596 struct thread *td = curthread; 597 598 return ((td->td_pflags & TDP_ALTSTACK) ? 599 #if defined(COMPAT_43) 600 ((td->td_sigstk.ss_size == 0) ? 601 (td->td_sigstk.ss_flags & SS_ONSTACK) : 602 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 603 #else 604 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 605 #endif 606 : 0); 607 } 608 609 static __inline int 610 sigprop(int sig) 611 { 612 613 if (sig > 0 && sig < NSIG) 614 return (sigproptbl[_SIG_IDX(sig)]); 615 return (0); 616 } 617 618 int 619 sig_ffs(sigset_t *set) 620 { 621 int i; 622 623 for (i = 0; i < _SIG_WORDS; i++) 624 if (set->__bits[i]) 625 return (ffs(set->__bits[i]) + (i * 32)); 626 return (0); 627 } 628 629 static bool 630 sigact_flag_test(struct sigaction *act, int flag) 631 { 632 633 /* 634 * SA_SIGINFO is reset when signal disposition is set to 635 * ignore or default. Other flags are kept according to user 636 * settings. 637 */ 638 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 639 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 640 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 641 } 642 643 /* 644 * kern_sigaction 645 * sigaction 646 * freebsd4_sigaction 647 * osigaction 648 */ 649 int 650 kern_sigaction(td, sig, act, oact, flags) 651 struct thread *td; 652 register int sig; 653 struct sigaction *act, *oact; 654 int flags; 655 { 656 struct sigacts *ps; 657 struct proc *p = td->td_proc; 658 659 if (!_SIG_VALID(sig)) 660 return (EINVAL); 661 if (act != NULL && (act->sa_flags & ~(SA_ONSTACK | SA_RESTART | 662 SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | SA_NOCLDWAIT | 663 SA_SIGINFO)) != 0) 664 return (EINVAL); 665 666 PROC_LOCK(p); 667 ps = p->p_sigacts; 668 mtx_lock(&ps->ps_mtx); 669 if (oact) { 670 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 671 oact->sa_flags = 0; 672 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 673 oact->sa_flags |= SA_ONSTACK; 674 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 675 oact->sa_flags |= SA_RESTART; 676 if (SIGISMEMBER(ps->ps_sigreset, sig)) 677 oact->sa_flags |= SA_RESETHAND; 678 if (SIGISMEMBER(ps->ps_signodefer, sig)) 679 oact->sa_flags |= SA_NODEFER; 680 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 681 oact->sa_flags |= SA_SIGINFO; 682 oact->sa_sigaction = 683 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 684 } else 685 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 686 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 687 oact->sa_flags |= SA_NOCLDSTOP; 688 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 689 oact->sa_flags |= SA_NOCLDWAIT; 690 } 691 if (act) { 692 if ((sig == SIGKILL || sig == SIGSTOP) && 693 act->sa_handler != SIG_DFL) { 694 mtx_unlock(&ps->ps_mtx); 695 PROC_UNLOCK(p); 696 return (EINVAL); 697 } 698 699 /* 700 * Change setting atomically. 701 */ 702 703 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 704 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 705 if (sigact_flag_test(act, SA_SIGINFO)) { 706 ps->ps_sigact[_SIG_IDX(sig)] = 707 (__sighandler_t *)act->sa_sigaction; 708 SIGADDSET(ps->ps_siginfo, sig); 709 } else { 710 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 711 SIGDELSET(ps->ps_siginfo, sig); 712 } 713 if (!sigact_flag_test(act, SA_RESTART)) 714 SIGADDSET(ps->ps_sigintr, sig); 715 else 716 SIGDELSET(ps->ps_sigintr, sig); 717 if (sigact_flag_test(act, SA_ONSTACK)) 718 SIGADDSET(ps->ps_sigonstack, sig); 719 else 720 SIGDELSET(ps->ps_sigonstack, sig); 721 if (sigact_flag_test(act, SA_RESETHAND)) 722 SIGADDSET(ps->ps_sigreset, sig); 723 else 724 SIGDELSET(ps->ps_sigreset, sig); 725 if (sigact_flag_test(act, SA_NODEFER)) 726 SIGADDSET(ps->ps_signodefer, sig); 727 else 728 SIGDELSET(ps->ps_signodefer, sig); 729 if (sig == SIGCHLD) { 730 if (act->sa_flags & SA_NOCLDSTOP) 731 ps->ps_flag |= PS_NOCLDSTOP; 732 else 733 ps->ps_flag &= ~PS_NOCLDSTOP; 734 if (act->sa_flags & SA_NOCLDWAIT) { 735 /* 736 * Paranoia: since SA_NOCLDWAIT is implemented 737 * by reparenting the dying child to PID 1 (and 738 * trust it to reap the zombie), PID 1 itself 739 * is forbidden to set SA_NOCLDWAIT. 740 */ 741 if (p->p_pid == 1) 742 ps->ps_flag &= ~PS_NOCLDWAIT; 743 else 744 ps->ps_flag |= PS_NOCLDWAIT; 745 } else 746 ps->ps_flag &= ~PS_NOCLDWAIT; 747 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 748 ps->ps_flag |= PS_CLDSIGIGN; 749 else 750 ps->ps_flag &= ~PS_CLDSIGIGN; 751 } 752 /* 753 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 754 * and for signals set to SIG_DFL where the default is to 755 * ignore. However, don't put SIGCONT in ps_sigignore, as we 756 * have to restart the process. 757 */ 758 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 759 (sigprop(sig) & SA_IGNORE && 760 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 761 /* never to be seen again */ 762 sigqueue_delete_proc(p, sig); 763 if (sig != SIGCONT) 764 /* easier in psignal */ 765 SIGADDSET(ps->ps_sigignore, sig); 766 SIGDELSET(ps->ps_sigcatch, sig); 767 } else { 768 SIGDELSET(ps->ps_sigignore, sig); 769 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 770 SIGDELSET(ps->ps_sigcatch, sig); 771 else 772 SIGADDSET(ps->ps_sigcatch, sig); 773 } 774 #ifdef COMPAT_FREEBSD4 775 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 776 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 777 (flags & KSA_FREEBSD4) == 0) 778 SIGDELSET(ps->ps_freebsd4, sig); 779 else 780 SIGADDSET(ps->ps_freebsd4, sig); 781 #endif 782 #ifdef COMPAT_43 783 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 784 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 785 (flags & KSA_OSIGSET) == 0) 786 SIGDELSET(ps->ps_osigset, sig); 787 else 788 SIGADDSET(ps->ps_osigset, sig); 789 #endif 790 } 791 mtx_unlock(&ps->ps_mtx); 792 PROC_UNLOCK(p); 793 return (0); 794 } 795 796 #ifndef _SYS_SYSPROTO_H_ 797 struct sigaction_args { 798 int sig; 799 struct sigaction *act; 800 struct sigaction *oact; 801 }; 802 #endif 803 int 804 sys_sigaction(td, uap) 805 struct thread *td; 806 register struct sigaction_args *uap; 807 { 808 struct sigaction act, oact; 809 register struct sigaction *actp, *oactp; 810 int error; 811 812 actp = (uap->act != NULL) ? &act : NULL; 813 oactp = (uap->oact != NULL) ? &oact : NULL; 814 if (actp) { 815 error = copyin(uap->act, actp, sizeof(act)); 816 if (error) 817 return (error); 818 } 819 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 820 if (oactp && !error) 821 error = copyout(oactp, uap->oact, sizeof(oact)); 822 return (error); 823 } 824 825 #ifdef COMPAT_FREEBSD4 826 #ifndef _SYS_SYSPROTO_H_ 827 struct freebsd4_sigaction_args { 828 int sig; 829 struct sigaction *act; 830 struct sigaction *oact; 831 }; 832 #endif 833 int 834 freebsd4_sigaction(td, uap) 835 struct thread *td; 836 register struct freebsd4_sigaction_args *uap; 837 { 838 struct sigaction act, oact; 839 register struct sigaction *actp, *oactp; 840 int error; 841 842 843 actp = (uap->act != NULL) ? &act : NULL; 844 oactp = (uap->oact != NULL) ? &oact : NULL; 845 if (actp) { 846 error = copyin(uap->act, actp, sizeof(act)); 847 if (error) 848 return (error); 849 } 850 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 851 if (oactp && !error) 852 error = copyout(oactp, uap->oact, sizeof(oact)); 853 return (error); 854 } 855 #endif /* COMAPT_FREEBSD4 */ 856 857 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 858 #ifndef _SYS_SYSPROTO_H_ 859 struct osigaction_args { 860 int signum; 861 struct osigaction *nsa; 862 struct osigaction *osa; 863 }; 864 #endif 865 int 866 osigaction(td, uap) 867 struct thread *td; 868 register struct osigaction_args *uap; 869 { 870 struct osigaction sa; 871 struct sigaction nsa, osa; 872 register struct sigaction *nsap, *osap; 873 int error; 874 875 if (uap->signum <= 0 || uap->signum >= ONSIG) 876 return (EINVAL); 877 878 nsap = (uap->nsa != NULL) ? &nsa : NULL; 879 osap = (uap->osa != NULL) ? &osa : NULL; 880 881 if (nsap) { 882 error = copyin(uap->nsa, &sa, sizeof(sa)); 883 if (error) 884 return (error); 885 nsap->sa_handler = sa.sa_handler; 886 nsap->sa_flags = sa.sa_flags; 887 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 888 } 889 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 890 if (osap && !error) { 891 sa.sa_handler = osap->sa_handler; 892 sa.sa_flags = osap->sa_flags; 893 SIG2OSIG(osap->sa_mask, sa.sa_mask); 894 error = copyout(&sa, uap->osa, sizeof(sa)); 895 } 896 return (error); 897 } 898 899 #if !defined(__i386__) 900 /* Avoid replicating the same stub everywhere */ 901 int 902 osigreturn(td, uap) 903 struct thread *td; 904 struct osigreturn_args *uap; 905 { 906 907 return (nosys(td, (struct nosys_args *)uap)); 908 } 909 #endif 910 #endif /* COMPAT_43 */ 911 912 /* 913 * Initialize signal state for process 0; 914 * set to ignore signals that are ignored by default. 915 */ 916 void 917 siginit(p) 918 struct proc *p; 919 { 920 register int i; 921 struct sigacts *ps; 922 923 PROC_LOCK(p); 924 ps = p->p_sigacts; 925 mtx_lock(&ps->ps_mtx); 926 for (i = 1; i <= NSIG; i++) { 927 if (sigprop(i) & SA_IGNORE && i != SIGCONT) { 928 SIGADDSET(ps->ps_sigignore, i); 929 } 930 } 931 mtx_unlock(&ps->ps_mtx); 932 PROC_UNLOCK(p); 933 } 934 935 /* 936 * Reset specified signal to the default disposition. 937 */ 938 static void 939 sigdflt(struct sigacts *ps, int sig) 940 { 941 942 mtx_assert(&ps->ps_mtx, MA_OWNED); 943 SIGDELSET(ps->ps_sigcatch, sig); 944 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT) 945 SIGADDSET(ps->ps_sigignore, sig); 946 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 947 SIGDELSET(ps->ps_siginfo, sig); 948 } 949 950 /* 951 * Reset signals for an exec of the specified process. 952 */ 953 void 954 execsigs(struct proc *p) 955 { 956 struct sigacts *ps; 957 int sig; 958 struct thread *td; 959 960 /* 961 * Reset caught signals. Held signals remain held 962 * through td_sigmask (unless they were caught, 963 * and are now ignored by default). 964 */ 965 PROC_LOCK_ASSERT(p, MA_OWNED); 966 td = FIRST_THREAD_IN_PROC(p); 967 ps = p->p_sigacts; 968 mtx_lock(&ps->ps_mtx); 969 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 970 sig = sig_ffs(&ps->ps_sigcatch); 971 sigdflt(ps, sig); 972 if ((sigprop(sig) & SA_IGNORE) != 0) 973 sigqueue_delete_proc(p, sig); 974 } 975 /* 976 * Reset stack state to the user stack. 977 * Clear set of signals caught on the signal stack. 978 */ 979 td->td_sigstk.ss_flags = SS_DISABLE; 980 td->td_sigstk.ss_size = 0; 981 td->td_sigstk.ss_sp = 0; 982 td->td_pflags &= ~TDP_ALTSTACK; 983 /* 984 * Reset no zombies if child dies flag as Solaris does. 985 */ 986 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 987 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 988 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 989 mtx_unlock(&ps->ps_mtx); 990 } 991 992 /* 993 * kern_sigprocmask() 994 * 995 * Manipulate signal mask. 996 */ 997 int 998 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 999 int flags) 1000 { 1001 sigset_t new_block, oset1; 1002 struct proc *p; 1003 int error; 1004 1005 p = td->td_proc; 1006 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1007 PROC_LOCK(p); 1008 if (oset != NULL) 1009 *oset = td->td_sigmask; 1010 1011 error = 0; 1012 if (set != NULL) { 1013 switch (how) { 1014 case SIG_BLOCK: 1015 SIG_CANTMASK(*set); 1016 oset1 = td->td_sigmask; 1017 SIGSETOR(td->td_sigmask, *set); 1018 new_block = td->td_sigmask; 1019 SIGSETNAND(new_block, oset1); 1020 break; 1021 case SIG_UNBLOCK: 1022 SIGSETNAND(td->td_sigmask, *set); 1023 signotify(td); 1024 goto out; 1025 case SIG_SETMASK: 1026 SIG_CANTMASK(*set); 1027 oset1 = td->td_sigmask; 1028 if (flags & SIGPROCMASK_OLD) 1029 SIGSETLO(td->td_sigmask, *set); 1030 else 1031 td->td_sigmask = *set; 1032 new_block = td->td_sigmask; 1033 SIGSETNAND(new_block, oset1); 1034 signotify(td); 1035 break; 1036 default: 1037 error = EINVAL; 1038 goto out; 1039 } 1040 1041 /* 1042 * The new_block set contains signals that were not previously 1043 * blocked, but are blocked now. 1044 * 1045 * In case we block any signal that was not previously blocked 1046 * for td, and process has the signal pending, try to schedule 1047 * signal delivery to some thread that does not block the 1048 * signal, possibly waking it up. 1049 */ 1050 if (p->p_numthreads != 1) 1051 reschedule_signals(p, new_block, flags); 1052 } 1053 1054 out: 1055 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1056 PROC_UNLOCK(p); 1057 return (error); 1058 } 1059 1060 #ifndef _SYS_SYSPROTO_H_ 1061 struct sigprocmask_args { 1062 int how; 1063 const sigset_t *set; 1064 sigset_t *oset; 1065 }; 1066 #endif 1067 int 1068 sys_sigprocmask(td, uap) 1069 register struct thread *td; 1070 struct sigprocmask_args *uap; 1071 { 1072 sigset_t set, oset; 1073 sigset_t *setp, *osetp; 1074 int error; 1075 1076 setp = (uap->set != NULL) ? &set : NULL; 1077 osetp = (uap->oset != NULL) ? &oset : NULL; 1078 if (setp) { 1079 error = copyin(uap->set, setp, sizeof(set)); 1080 if (error) 1081 return (error); 1082 } 1083 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1084 if (osetp && !error) { 1085 error = copyout(osetp, uap->oset, sizeof(oset)); 1086 } 1087 return (error); 1088 } 1089 1090 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1091 #ifndef _SYS_SYSPROTO_H_ 1092 struct osigprocmask_args { 1093 int how; 1094 osigset_t mask; 1095 }; 1096 #endif 1097 int 1098 osigprocmask(td, uap) 1099 register struct thread *td; 1100 struct osigprocmask_args *uap; 1101 { 1102 sigset_t set, oset; 1103 int error; 1104 1105 OSIG2SIG(uap->mask, set); 1106 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1107 SIG2OSIG(oset, td->td_retval[0]); 1108 return (error); 1109 } 1110 #endif /* COMPAT_43 */ 1111 1112 int 1113 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1114 { 1115 ksiginfo_t ksi; 1116 sigset_t set; 1117 int error; 1118 1119 error = copyin(uap->set, &set, sizeof(set)); 1120 if (error) { 1121 td->td_retval[0] = error; 1122 return (0); 1123 } 1124 1125 error = kern_sigtimedwait(td, set, &ksi, NULL); 1126 if (error) { 1127 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1128 error = ERESTART; 1129 if (error == ERESTART) 1130 return (error); 1131 td->td_retval[0] = error; 1132 return (0); 1133 } 1134 1135 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1136 td->td_retval[0] = error; 1137 return (0); 1138 } 1139 1140 int 1141 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1142 { 1143 struct timespec ts; 1144 struct timespec *timeout; 1145 sigset_t set; 1146 ksiginfo_t ksi; 1147 int error; 1148 1149 if (uap->timeout) { 1150 error = copyin(uap->timeout, &ts, sizeof(ts)); 1151 if (error) 1152 return (error); 1153 1154 timeout = &ts; 1155 } else 1156 timeout = NULL; 1157 1158 error = copyin(uap->set, &set, sizeof(set)); 1159 if (error) 1160 return (error); 1161 1162 error = kern_sigtimedwait(td, set, &ksi, timeout); 1163 if (error) 1164 return (error); 1165 1166 if (uap->info) 1167 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1168 1169 if (error == 0) 1170 td->td_retval[0] = ksi.ksi_signo; 1171 return (error); 1172 } 1173 1174 int 1175 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1176 { 1177 ksiginfo_t ksi; 1178 sigset_t set; 1179 int error; 1180 1181 error = copyin(uap->set, &set, sizeof(set)); 1182 if (error) 1183 return (error); 1184 1185 error = kern_sigtimedwait(td, set, &ksi, NULL); 1186 if (error) 1187 return (error); 1188 1189 if (uap->info) 1190 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1191 1192 if (error == 0) 1193 td->td_retval[0] = ksi.ksi_signo; 1194 return (error); 1195 } 1196 1197 int 1198 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1199 struct timespec *timeout) 1200 { 1201 struct sigacts *ps; 1202 sigset_t saved_mask, new_block; 1203 struct proc *p; 1204 int error, sig, timo, timevalid = 0; 1205 struct timespec rts, ets, ts; 1206 struct timeval tv; 1207 1208 p = td->td_proc; 1209 error = 0; 1210 ets.tv_sec = 0; 1211 ets.tv_nsec = 0; 1212 1213 if (timeout != NULL) { 1214 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1215 timevalid = 1; 1216 getnanouptime(&rts); 1217 ets = rts; 1218 timespecadd(&ets, timeout); 1219 } 1220 } 1221 ksiginfo_init(ksi); 1222 /* Some signals can not be waited for. */ 1223 SIG_CANTMASK(waitset); 1224 ps = p->p_sigacts; 1225 PROC_LOCK(p); 1226 saved_mask = td->td_sigmask; 1227 SIGSETNAND(td->td_sigmask, waitset); 1228 for (;;) { 1229 mtx_lock(&ps->ps_mtx); 1230 sig = cursig(td); 1231 mtx_unlock(&ps->ps_mtx); 1232 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1233 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1234 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1235 error = 0; 1236 break; 1237 } 1238 } 1239 1240 if (error != 0) 1241 break; 1242 1243 /* 1244 * POSIX says this must be checked after looking for pending 1245 * signals. 1246 */ 1247 if (timeout != NULL) { 1248 if (!timevalid) { 1249 error = EINVAL; 1250 break; 1251 } 1252 getnanouptime(&rts); 1253 if (timespeccmp(&rts, &ets, >=)) { 1254 error = EAGAIN; 1255 break; 1256 } 1257 ts = ets; 1258 timespecsub(&ts, &rts); 1259 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1260 timo = tvtohz(&tv); 1261 } else { 1262 timo = 0; 1263 } 1264 1265 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1266 1267 if (timeout != NULL) { 1268 if (error == ERESTART) { 1269 /* Timeout can not be restarted. */ 1270 error = EINTR; 1271 } else if (error == EAGAIN) { 1272 /* We will calculate timeout by ourself. */ 1273 error = 0; 1274 } 1275 } 1276 } 1277 1278 new_block = saved_mask; 1279 SIGSETNAND(new_block, td->td_sigmask); 1280 td->td_sigmask = saved_mask; 1281 /* 1282 * Fewer signals can be delivered to us, reschedule signal 1283 * notification. 1284 */ 1285 if (p->p_numthreads != 1) 1286 reschedule_signals(p, new_block, 0); 1287 1288 if (error == 0) { 1289 SDT_PROBE(proc, kernel, , signal__clear, sig, ksi, 0, 0, 0); 1290 1291 if (ksi->ksi_code == SI_TIMER) 1292 itimer_accept(p, ksi->ksi_timerid, ksi); 1293 1294 #ifdef KTRACE 1295 if (KTRPOINT(td, KTR_PSIG)) { 1296 sig_t action; 1297 1298 mtx_lock(&ps->ps_mtx); 1299 action = ps->ps_sigact[_SIG_IDX(sig)]; 1300 mtx_unlock(&ps->ps_mtx); 1301 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1302 } 1303 #endif 1304 if (sig == SIGKILL) 1305 sigexit(td, sig); 1306 } 1307 PROC_UNLOCK(p); 1308 return (error); 1309 } 1310 1311 #ifndef _SYS_SYSPROTO_H_ 1312 struct sigpending_args { 1313 sigset_t *set; 1314 }; 1315 #endif 1316 int 1317 sys_sigpending(td, uap) 1318 struct thread *td; 1319 struct sigpending_args *uap; 1320 { 1321 struct proc *p = td->td_proc; 1322 sigset_t pending; 1323 1324 PROC_LOCK(p); 1325 pending = p->p_sigqueue.sq_signals; 1326 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1327 PROC_UNLOCK(p); 1328 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1329 } 1330 1331 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1332 #ifndef _SYS_SYSPROTO_H_ 1333 struct osigpending_args { 1334 int dummy; 1335 }; 1336 #endif 1337 int 1338 osigpending(td, uap) 1339 struct thread *td; 1340 struct osigpending_args *uap; 1341 { 1342 struct proc *p = td->td_proc; 1343 sigset_t pending; 1344 1345 PROC_LOCK(p); 1346 pending = p->p_sigqueue.sq_signals; 1347 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1348 PROC_UNLOCK(p); 1349 SIG2OSIG(pending, td->td_retval[0]); 1350 return (0); 1351 } 1352 #endif /* COMPAT_43 */ 1353 1354 #if defined(COMPAT_43) 1355 /* 1356 * Generalized interface signal handler, 4.3-compatible. 1357 */ 1358 #ifndef _SYS_SYSPROTO_H_ 1359 struct osigvec_args { 1360 int signum; 1361 struct sigvec *nsv; 1362 struct sigvec *osv; 1363 }; 1364 #endif 1365 /* ARGSUSED */ 1366 int 1367 osigvec(td, uap) 1368 struct thread *td; 1369 register struct osigvec_args *uap; 1370 { 1371 struct sigvec vec; 1372 struct sigaction nsa, osa; 1373 register struct sigaction *nsap, *osap; 1374 int error; 1375 1376 if (uap->signum <= 0 || uap->signum >= ONSIG) 1377 return (EINVAL); 1378 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1379 osap = (uap->osv != NULL) ? &osa : NULL; 1380 if (nsap) { 1381 error = copyin(uap->nsv, &vec, sizeof(vec)); 1382 if (error) 1383 return (error); 1384 nsap->sa_handler = vec.sv_handler; 1385 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1386 nsap->sa_flags = vec.sv_flags; 1387 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1388 } 1389 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1390 if (osap && !error) { 1391 vec.sv_handler = osap->sa_handler; 1392 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1393 vec.sv_flags = osap->sa_flags; 1394 vec.sv_flags &= ~SA_NOCLDWAIT; 1395 vec.sv_flags ^= SA_RESTART; 1396 error = copyout(&vec, uap->osv, sizeof(vec)); 1397 } 1398 return (error); 1399 } 1400 1401 #ifndef _SYS_SYSPROTO_H_ 1402 struct osigblock_args { 1403 int mask; 1404 }; 1405 #endif 1406 int 1407 osigblock(td, uap) 1408 register struct thread *td; 1409 struct osigblock_args *uap; 1410 { 1411 sigset_t set, oset; 1412 1413 OSIG2SIG(uap->mask, set); 1414 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1415 SIG2OSIG(oset, td->td_retval[0]); 1416 return (0); 1417 } 1418 1419 #ifndef _SYS_SYSPROTO_H_ 1420 struct osigsetmask_args { 1421 int mask; 1422 }; 1423 #endif 1424 int 1425 osigsetmask(td, uap) 1426 struct thread *td; 1427 struct osigsetmask_args *uap; 1428 { 1429 sigset_t set, oset; 1430 1431 OSIG2SIG(uap->mask, set); 1432 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1433 SIG2OSIG(oset, td->td_retval[0]); 1434 return (0); 1435 } 1436 #endif /* COMPAT_43 */ 1437 1438 /* 1439 * Suspend calling thread until signal, providing mask to be set in the 1440 * meantime. 1441 */ 1442 #ifndef _SYS_SYSPROTO_H_ 1443 struct sigsuspend_args { 1444 const sigset_t *sigmask; 1445 }; 1446 #endif 1447 /* ARGSUSED */ 1448 int 1449 sys_sigsuspend(td, uap) 1450 struct thread *td; 1451 struct sigsuspend_args *uap; 1452 { 1453 sigset_t mask; 1454 int error; 1455 1456 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1457 if (error) 1458 return (error); 1459 return (kern_sigsuspend(td, mask)); 1460 } 1461 1462 int 1463 kern_sigsuspend(struct thread *td, sigset_t mask) 1464 { 1465 struct proc *p = td->td_proc; 1466 int has_sig, sig; 1467 1468 /* 1469 * When returning from sigsuspend, we want 1470 * the old mask to be restored after the 1471 * signal handler has finished. Thus, we 1472 * save it here and mark the sigacts structure 1473 * to indicate this. 1474 */ 1475 PROC_LOCK(p); 1476 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1477 SIGPROCMASK_PROC_LOCKED); 1478 td->td_pflags |= TDP_OLDMASK; 1479 1480 /* 1481 * Process signals now. Otherwise, we can get spurious wakeup 1482 * due to signal entered process queue, but delivered to other 1483 * thread. But sigsuspend should return only on signal 1484 * delivery. 1485 */ 1486 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1487 for (has_sig = 0; !has_sig;) { 1488 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1489 0) == 0) 1490 /* void */; 1491 thread_suspend_check(0); 1492 mtx_lock(&p->p_sigacts->ps_mtx); 1493 while ((sig = cursig(td)) != 0) 1494 has_sig += postsig(sig); 1495 mtx_unlock(&p->p_sigacts->ps_mtx); 1496 } 1497 PROC_UNLOCK(p); 1498 td->td_errno = EINTR; 1499 td->td_pflags |= TDP_NERRNO; 1500 return (EJUSTRETURN); 1501 } 1502 1503 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1504 /* 1505 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1506 * convention: libc stub passes mask, not pointer, to save a copyin. 1507 */ 1508 #ifndef _SYS_SYSPROTO_H_ 1509 struct osigsuspend_args { 1510 osigset_t mask; 1511 }; 1512 #endif 1513 /* ARGSUSED */ 1514 int 1515 osigsuspend(td, uap) 1516 struct thread *td; 1517 struct osigsuspend_args *uap; 1518 { 1519 sigset_t mask; 1520 1521 OSIG2SIG(uap->mask, mask); 1522 return (kern_sigsuspend(td, mask)); 1523 } 1524 #endif /* COMPAT_43 */ 1525 1526 #if defined(COMPAT_43) 1527 #ifndef _SYS_SYSPROTO_H_ 1528 struct osigstack_args { 1529 struct sigstack *nss; 1530 struct sigstack *oss; 1531 }; 1532 #endif 1533 /* ARGSUSED */ 1534 int 1535 osigstack(td, uap) 1536 struct thread *td; 1537 register struct osigstack_args *uap; 1538 { 1539 struct sigstack nss, oss; 1540 int error = 0; 1541 1542 if (uap->nss != NULL) { 1543 error = copyin(uap->nss, &nss, sizeof(nss)); 1544 if (error) 1545 return (error); 1546 } 1547 oss.ss_sp = td->td_sigstk.ss_sp; 1548 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1549 if (uap->nss != NULL) { 1550 td->td_sigstk.ss_sp = nss.ss_sp; 1551 td->td_sigstk.ss_size = 0; 1552 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1553 td->td_pflags |= TDP_ALTSTACK; 1554 } 1555 if (uap->oss != NULL) 1556 error = copyout(&oss, uap->oss, sizeof(oss)); 1557 1558 return (error); 1559 } 1560 #endif /* COMPAT_43 */ 1561 1562 #ifndef _SYS_SYSPROTO_H_ 1563 struct sigaltstack_args { 1564 stack_t *ss; 1565 stack_t *oss; 1566 }; 1567 #endif 1568 /* ARGSUSED */ 1569 int 1570 sys_sigaltstack(td, uap) 1571 struct thread *td; 1572 register struct sigaltstack_args *uap; 1573 { 1574 stack_t ss, oss; 1575 int error; 1576 1577 if (uap->ss != NULL) { 1578 error = copyin(uap->ss, &ss, sizeof(ss)); 1579 if (error) 1580 return (error); 1581 } 1582 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1583 (uap->oss != NULL) ? &oss : NULL); 1584 if (error) 1585 return (error); 1586 if (uap->oss != NULL) 1587 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1588 return (error); 1589 } 1590 1591 int 1592 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1593 { 1594 struct proc *p = td->td_proc; 1595 int oonstack; 1596 1597 oonstack = sigonstack(cpu_getstack(td)); 1598 1599 if (oss != NULL) { 1600 *oss = td->td_sigstk; 1601 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1602 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1603 } 1604 1605 if (ss != NULL) { 1606 if (oonstack) 1607 return (EPERM); 1608 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1609 return (EINVAL); 1610 if (!(ss->ss_flags & SS_DISABLE)) { 1611 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1612 return (ENOMEM); 1613 1614 td->td_sigstk = *ss; 1615 td->td_pflags |= TDP_ALTSTACK; 1616 } else { 1617 td->td_pflags &= ~TDP_ALTSTACK; 1618 } 1619 } 1620 return (0); 1621 } 1622 1623 /* 1624 * Common code for kill process group/broadcast kill. 1625 * cp is calling process. 1626 */ 1627 static int 1628 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1629 { 1630 struct proc *p; 1631 struct pgrp *pgrp; 1632 int err; 1633 int ret; 1634 1635 ret = ESRCH; 1636 if (all) { 1637 /* 1638 * broadcast 1639 */ 1640 sx_slock(&allproc_lock); 1641 FOREACH_PROC_IN_SYSTEM(p) { 1642 PROC_LOCK(p); 1643 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1644 p == td->td_proc || p->p_state == PRS_NEW) { 1645 PROC_UNLOCK(p); 1646 continue; 1647 } 1648 err = p_cansignal(td, p, sig); 1649 if (err == 0) { 1650 if (sig) 1651 pksignal(p, sig, ksi); 1652 ret = err; 1653 } 1654 else if (ret == ESRCH) 1655 ret = err; 1656 PROC_UNLOCK(p); 1657 } 1658 sx_sunlock(&allproc_lock); 1659 } else { 1660 sx_slock(&proctree_lock); 1661 if (pgid == 0) { 1662 /* 1663 * zero pgid means send to my process group. 1664 */ 1665 pgrp = td->td_proc->p_pgrp; 1666 PGRP_LOCK(pgrp); 1667 } else { 1668 pgrp = pgfind(pgid); 1669 if (pgrp == NULL) { 1670 sx_sunlock(&proctree_lock); 1671 return (ESRCH); 1672 } 1673 } 1674 sx_sunlock(&proctree_lock); 1675 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1676 PROC_LOCK(p); 1677 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1678 p->p_state == PRS_NEW) { 1679 PROC_UNLOCK(p); 1680 continue; 1681 } 1682 err = p_cansignal(td, p, sig); 1683 if (err == 0) { 1684 if (sig) 1685 pksignal(p, sig, ksi); 1686 ret = err; 1687 } 1688 else if (ret == ESRCH) 1689 ret = err; 1690 PROC_UNLOCK(p); 1691 } 1692 PGRP_UNLOCK(pgrp); 1693 } 1694 return (ret); 1695 } 1696 1697 #ifndef _SYS_SYSPROTO_H_ 1698 struct kill_args { 1699 int pid; 1700 int signum; 1701 }; 1702 #endif 1703 /* ARGSUSED */ 1704 int 1705 sys_kill(struct thread *td, struct kill_args *uap) 1706 { 1707 ksiginfo_t ksi; 1708 struct proc *p; 1709 int error; 1710 1711 /* 1712 * A process in capability mode can send signals only to himself. 1713 * The main rationale behind this is that abort(3) is implemented as 1714 * kill(getpid(), SIGABRT). 1715 */ 1716 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1717 return (ECAPMODE); 1718 1719 AUDIT_ARG_SIGNUM(uap->signum); 1720 AUDIT_ARG_PID(uap->pid); 1721 if ((u_int)uap->signum > _SIG_MAXSIG) 1722 return (EINVAL); 1723 1724 ksiginfo_init(&ksi); 1725 ksi.ksi_signo = uap->signum; 1726 ksi.ksi_code = SI_USER; 1727 ksi.ksi_pid = td->td_proc->p_pid; 1728 ksi.ksi_uid = td->td_ucred->cr_ruid; 1729 1730 if (uap->pid > 0) { 1731 /* kill single process */ 1732 if ((p = pfind(uap->pid)) == NULL) { 1733 if ((p = zpfind(uap->pid)) == NULL) 1734 return (ESRCH); 1735 } 1736 AUDIT_ARG_PROCESS(p); 1737 error = p_cansignal(td, p, uap->signum); 1738 if (error == 0 && uap->signum) 1739 pksignal(p, uap->signum, &ksi); 1740 PROC_UNLOCK(p); 1741 return (error); 1742 } 1743 switch (uap->pid) { 1744 case -1: /* broadcast signal */ 1745 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1746 case 0: /* signal own process group */ 1747 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1748 default: /* negative explicit process group */ 1749 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1750 } 1751 /* NOTREACHED */ 1752 } 1753 1754 int 1755 sys_pdkill(td, uap) 1756 struct thread *td; 1757 struct pdkill_args *uap; 1758 { 1759 #ifdef PROCDESC 1760 struct proc *p; 1761 cap_rights_t rights; 1762 int error; 1763 1764 AUDIT_ARG_SIGNUM(uap->signum); 1765 AUDIT_ARG_FD(uap->fd); 1766 if ((u_int)uap->signum > _SIG_MAXSIG) 1767 return (EINVAL); 1768 1769 error = procdesc_find(td, uap->fd, 1770 cap_rights_init(&rights, CAP_PDKILL), &p); 1771 if (error) 1772 return (error); 1773 AUDIT_ARG_PROCESS(p); 1774 error = p_cansignal(td, p, uap->signum); 1775 if (error == 0 && uap->signum) 1776 kern_psignal(p, uap->signum); 1777 PROC_UNLOCK(p); 1778 return (error); 1779 #else 1780 return (ENOSYS); 1781 #endif 1782 } 1783 1784 #if defined(COMPAT_43) 1785 #ifndef _SYS_SYSPROTO_H_ 1786 struct okillpg_args { 1787 int pgid; 1788 int signum; 1789 }; 1790 #endif 1791 /* ARGSUSED */ 1792 int 1793 okillpg(struct thread *td, struct okillpg_args *uap) 1794 { 1795 ksiginfo_t ksi; 1796 1797 AUDIT_ARG_SIGNUM(uap->signum); 1798 AUDIT_ARG_PID(uap->pgid); 1799 if ((u_int)uap->signum > _SIG_MAXSIG) 1800 return (EINVAL); 1801 1802 ksiginfo_init(&ksi); 1803 ksi.ksi_signo = uap->signum; 1804 ksi.ksi_code = SI_USER; 1805 ksi.ksi_pid = td->td_proc->p_pid; 1806 ksi.ksi_uid = td->td_ucred->cr_ruid; 1807 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1808 } 1809 #endif /* COMPAT_43 */ 1810 1811 #ifndef _SYS_SYSPROTO_H_ 1812 struct sigqueue_args { 1813 pid_t pid; 1814 int signum; 1815 /* union sigval */ void *value; 1816 }; 1817 #endif 1818 int 1819 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1820 { 1821 ksiginfo_t ksi; 1822 struct proc *p; 1823 int error; 1824 1825 if ((u_int)uap->signum > _SIG_MAXSIG) 1826 return (EINVAL); 1827 1828 /* 1829 * Specification says sigqueue can only send signal to 1830 * single process. 1831 */ 1832 if (uap->pid <= 0) 1833 return (EINVAL); 1834 1835 if ((p = pfind(uap->pid)) == NULL) { 1836 if ((p = zpfind(uap->pid)) == NULL) 1837 return (ESRCH); 1838 } 1839 error = p_cansignal(td, p, uap->signum); 1840 if (error == 0 && uap->signum != 0) { 1841 ksiginfo_init(&ksi); 1842 ksi.ksi_flags = KSI_SIGQ; 1843 ksi.ksi_signo = uap->signum; 1844 ksi.ksi_code = SI_QUEUE; 1845 ksi.ksi_pid = td->td_proc->p_pid; 1846 ksi.ksi_uid = td->td_ucred->cr_ruid; 1847 ksi.ksi_value.sival_ptr = uap->value; 1848 error = pksignal(p, ksi.ksi_signo, &ksi); 1849 } 1850 PROC_UNLOCK(p); 1851 return (error); 1852 } 1853 1854 /* 1855 * Send a signal to a process group. 1856 */ 1857 void 1858 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1859 { 1860 struct pgrp *pgrp; 1861 1862 if (pgid != 0) { 1863 sx_slock(&proctree_lock); 1864 pgrp = pgfind(pgid); 1865 sx_sunlock(&proctree_lock); 1866 if (pgrp != NULL) { 1867 pgsignal(pgrp, sig, 0, ksi); 1868 PGRP_UNLOCK(pgrp); 1869 } 1870 } 1871 } 1872 1873 /* 1874 * Send a signal to a process group. If checktty is 1, 1875 * limit to members which have a controlling terminal. 1876 */ 1877 void 1878 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1879 { 1880 struct proc *p; 1881 1882 if (pgrp) { 1883 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1884 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1885 PROC_LOCK(p); 1886 if (p->p_state == PRS_NORMAL && 1887 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1888 pksignal(p, sig, ksi); 1889 PROC_UNLOCK(p); 1890 } 1891 } 1892 } 1893 1894 /* 1895 * Send a signal caused by a trap to the current thread. If it will be 1896 * caught immediately, deliver it with correct code. Otherwise, post it 1897 * normally. 1898 */ 1899 void 1900 trapsignal(struct thread *td, ksiginfo_t *ksi) 1901 { 1902 struct sigacts *ps; 1903 sigset_t mask; 1904 struct proc *p; 1905 int sig; 1906 int code; 1907 1908 p = td->td_proc; 1909 sig = ksi->ksi_signo; 1910 code = ksi->ksi_code; 1911 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1912 1913 PROC_LOCK(p); 1914 ps = p->p_sigacts; 1915 mtx_lock(&ps->ps_mtx); 1916 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1917 !SIGISMEMBER(td->td_sigmask, sig)) { 1918 td->td_ru.ru_nsignals++; 1919 #ifdef KTRACE 1920 if (KTRPOINT(curthread, KTR_PSIG)) 1921 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1922 &td->td_sigmask, code); 1923 #endif 1924 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1925 ksi, &td->td_sigmask); 1926 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1927 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1928 SIGADDSET(mask, sig); 1929 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1930 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1931 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1932 sigdflt(ps, sig); 1933 mtx_unlock(&ps->ps_mtx); 1934 } else { 1935 /* 1936 * Avoid a possible infinite loop if the thread 1937 * masking the signal or process is ignoring the 1938 * signal. 1939 */ 1940 if (kern_forcesigexit && 1941 (SIGISMEMBER(td->td_sigmask, sig) || 1942 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1943 SIGDELSET(td->td_sigmask, sig); 1944 SIGDELSET(ps->ps_sigcatch, sig); 1945 SIGDELSET(ps->ps_sigignore, sig); 1946 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1947 } 1948 mtx_unlock(&ps->ps_mtx); 1949 p->p_code = code; /* XXX for core dump/debugger */ 1950 p->p_sig = sig; /* XXX to verify code */ 1951 tdsendsignal(p, td, sig, ksi); 1952 } 1953 PROC_UNLOCK(p); 1954 } 1955 1956 static struct thread * 1957 sigtd(struct proc *p, int sig, int prop) 1958 { 1959 struct thread *td, *signal_td; 1960 1961 PROC_LOCK_ASSERT(p, MA_OWNED); 1962 1963 /* 1964 * Check if current thread can handle the signal without 1965 * switching context to another thread. 1966 */ 1967 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1968 return (curthread); 1969 signal_td = NULL; 1970 FOREACH_THREAD_IN_PROC(p, td) { 1971 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1972 signal_td = td; 1973 break; 1974 } 1975 } 1976 if (signal_td == NULL) 1977 signal_td = FIRST_THREAD_IN_PROC(p); 1978 return (signal_td); 1979 } 1980 1981 /* 1982 * Send the signal to the process. If the signal has an action, the action 1983 * is usually performed by the target process rather than the caller; we add 1984 * the signal to the set of pending signals for the process. 1985 * 1986 * Exceptions: 1987 * o When a stop signal is sent to a sleeping process that takes the 1988 * default action, the process is stopped without awakening it. 1989 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1990 * regardless of the signal action (eg, blocked or ignored). 1991 * 1992 * Other ignored signals are discarded immediately. 1993 * 1994 * NB: This function may be entered from the debugger via the "kill" DDB 1995 * command. There is little that can be done to mitigate the possibly messy 1996 * side effects of this unwise possibility. 1997 */ 1998 void 1999 kern_psignal(struct proc *p, int sig) 2000 { 2001 ksiginfo_t ksi; 2002 2003 ksiginfo_init(&ksi); 2004 ksi.ksi_signo = sig; 2005 ksi.ksi_code = SI_KERNEL; 2006 (void) tdsendsignal(p, NULL, sig, &ksi); 2007 } 2008 2009 int 2010 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2011 { 2012 2013 return (tdsendsignal(p, NULL, sig, ksi)); 2014 } 2015 2016 /* Utility function for finding a thread to send signal event to. */ 2017 int 2018 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2019 { 2020 struct thread *td; 2021 2022 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2023 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2024 if (td == NULL) 2025 return (ESRCH); 2026 *ttd = td; 2027 } else { 2028 *ttd = NULL; 2029 PROC_LOCK(p); 2030 } 2031 return (0); 2032 } 2033 2034 void 2035 tdsignal(struct thread *td, int sig) 2036 { 2037 ksiginfo_t ksi; 2038 2039 ksiginfo_init(&ksi); 2040 ksi.ksi_signo = sig; 2041 ksi.ksi_code = SI_KERNEL; 2042 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2043 } 2044 2045 void 2046 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2047 { 2048 2049 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2050 } 2051 2052 int 2053 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2054 { 2055 sig_t action; 2056 sigqueue_t *sigqueue; 2057 int prop; 2058 struct sigacts *ps; 2059 int intrval; 2060 int ret = 0; 2061 int wakeup_swapper; 2062 2063 MPASS(td == NULL || p == td->td_proc); 2064 PROC_LOCK_ASSERT(p, MA_OWNED); 2065 2066 if (!_SIG_VALID(sig)) 2067 panic("%s(): invalid signal %d", __func__, sig); 2068 2069 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2070 2071 /* 2072 * IEEE Std 1003.1-2001: return success when killing a zombie. 2073 */ 2074 if (p->p_state == PRS_ZOMBIE) { 2075 if (ksi && (ksi->ksi_flags & KSI_INS)) 2076 ksiginfo_tryfree(ksi); 2077 return (ret); 2078 } 2079 2080 ps = p->p_sigacts; 2081 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2082 prop = sigprop(sig); 2083 2084 if (td == NULL) { 2085 td = sigtd(p, sig, prop); 2086 sigqueue = &p->p_sigqueue; 2087 } else 2088 sigqueue = &td->td_sigqueue; 2089 2090 SDT_PROBE(proc, kernel, , signal__send, td, p, sig, 0, 0 ); 2091 2092 /* 2093 * If the signal is being ignored, 2094 * then we forget about it immediately. 2095 * (Note: we don't set SIGCONT in ps_sigignore, 2096 * and if it is set to SIG_IGN, 2097 * action will be SIG_DFL here.) 2098 */ 2099 mtx_lock(&ps->ps_mtx); 2100 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2101 SDT_PROBE(proc, kernel, , signal__discard, td, p, sig, 0, 0 ); 2102 2103 mtx_unlock(&ps->ps_mtx); 2104 if (ksi && (ksi->ksi_flags & KSI_INS)) 2105 ksiginfo_tryfree(ksi); 2106 return (ret); 2107 } 2108 if (SIGISMEMBER(td->td_sigmask, sig)) 2109 action = SIG_HOLD; 2110 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2111 action = SIG_CATCH; 2112 else 2113 action = SIG_DFL; 2114 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2115 intrval = EINTR; 2116 else 2117 intrval = ERESTART; 2118 mtx_unlock(&ps->ps_mtx); 2119 2120 if (prop & SA_CONT) 2121 sigqueue_delete_stopmask_proc(p); 2122 else if (prop & SA_STOP) { 2123 /* 2124 * If sending a tty stop signal to a member of an orphaned 2125 * process group, discard the signal here if the action 2126 * is default; don't stop the process below if sleeping, 2127 * and don't clear any pending SIGCONT. 2128 */ 2129 if ((prop & SA_TTYSTOP) && 2130 (p->p_pgrp->pg_jobc == 0) && 2131 (action == SIG_DFL)) { 2132 if (ksi && (ksi->ksi_flags & KSI_INS)) 2133 ksiginfo_tryfree(ksi); 2134 return (ret); 2135 } 2136 sigqueue_delete_proc(p, SIGCONT); 2137 if (p->p_flag & P_CONTINUED) { 2138 p->p_flag &= ~P_CONTINUED; 2139 PROC_LOCK(p->p_pptr); 2140 sigqueue_take(p->p_ksi); 2141 PROC_UNLOCK(p->p_pptr); 2142 } 2143 } 2144 2145 ret = sigqueue_add(sigqueue, sig, ksi); 2146 if (ret != 0) 2147 return (ret); 2148 signotify(td); 2149 /* 2150 * Defer further processing for signals which are held, 2151 * except that stopped processes must be continued by SIGCONT. 2152 */ 2153 if (action == SIG_HOLD && 2154 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2155 return (ret); 2156 /* 2157 * SIGKILL: Remove procfs STOPEVENTs. 2158 */ 2159 if (sig == SIGKILL) { 2160 /* from procfs_ioctl.c: PIOCBIC */ 2161 p->p_stops = 0; 2162 /* from procfs_ioctl.c: PIOCCONT */ 2163 p->p_step = 0; 2164 wakeup(&p->p_step); 2165 } 2166 /* 2167 * Some signals have a process-wide effect and a per-thread 2168 * component. Most processing occurs when the process next 2169 * tries to cross the user boundary, however there are some 2170 * times when processing needs to be done immediately, such as 2171 * waking up threads so that they can cross the user boundary. 2172 * We try to do the per-process part here. 2173 */ 2174 if (P_SHOULDSTOP(p)) { 2175 KASSERT(!(p->p_flag & P_WEXIT), 2176 ("signal to stopped but exiting process")); 2177 if (sig == SIGKILL) { 2178 /* 2179 * If traced process is already stopped, 2180 * then no further action is necessary. 2181 */ 2182 if (p->p_flag & P_TRACED) 2183 goto out; 2184 /* 2185 * SIGKILL sets process running. 2186 * It will die elsewhere. 2187 * All threads must be restarted. 2188 */ 2189 p->p_flag &= ~P_STOPPED_SIG; 2190 goto runfast; 2191 } 2192 2193 if (prop & SA_CONT) { 2194 /* 2195 * If traced process is already stopped, 2196 * then no further action is necessary. 2197 */ 2198 if (p->p_flag & P_TRACED) 2199 goto out; 2200 /* 2201 * If SIGCONT is default (or ignored), we continue the 2202 * process but don't leave the signal in sigqueue as 2203 * it has no further action. If SIGCONT is held, we 2204 * continue the process and leave the signal in 2205 * sigqueue. If the process catches SIGCONT, let it 2206 * handle the signal itself. If it isn't waiting on 2207 * an event, it goes back to run state. 2208 * Otherwise, process goes back to sleep state. 2209 */ 2210 p->p_flag &= ~P_STOPPED_SIG; 2211 PROC_SLOCK(p); 2212 if (p->p_numthreads == p->p_suspcount) { 2213 PROC_SUNLOCK(p); 2214 p->p_flag |= P_CONTINUED; 2215 p->p_xstat = SIGCONT; 2216 PROC_LOCK(p->p_pptr); 2217 childproc_continued(p); 2218 PROC_UNLOCK(p->p_pptr); 2219 PROC_SLOCK(p); 2220 } 2221 if (action == SIG_DFL) { 2222 thread_unsuspend(p); 2223 PROC_SUNLOCK(p); 2224 sigqueue_delete(sigqueue, sig); 2225 goto out; 2226 } 2227 if (action == SIG_CATCH) { 2228 /* 2229 * The process wants to catch it so it needs 2230 * to run at least one thread, but which one? 2231 */ 2232 PROC_SUNLOCK(p); 2233 goto runfast; 2234 } 2235 /* 2236 * The signal is not ignored or caught. 2237 */ 2238 thread_unsuspend(p); 2239 PROC_SUNLOCK(p); 2240 goto out; 2241 } 2242 2243 if (prop & SA_STOP) { 2244 /* 2245 * If traced process is already stopped, 2246 * then no further action is necessary. 2247 */ 2248 if (p->p_flag & P_TRACED) 2249 goto out; 2250 /* 2251 * Already stopped, don't need to stop again 2252 * (If we did the shell could get confused). 2253 * Just make sure the signal STOP bit set. 2254 */ 2255 p->p_flag |= P_STOPPED_SIG; 2256 sigqueue_delete(sigqueue, sig); 2257 goto out; 2258 } 2259 2260 /* 2261 * All other kinds of signals: 2262 * If a thread is sleeping interruptibly, simulate a 2263 * wakeup so that when it is continued it will be made 2264 * runnable and can look at the signal. However, don't make 2265 * the PROCESS runnable, leave it stopped. 2266 * It may run a bit until it hits a thread_suspend_check(). 2267 */ 2268 wakeup_swapper = 0; 2269 PROC_SLOCK(p); 2270 thread_lock(td); 2271 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2272 wakeup_swapper = sleepq_abort(td, intrval); 2273 thread_unlock(td); 2274 PROC_SUNLOCK(p); 2275 if (wakeup_swapper) 2276 kick_proc0(); 2277 goto out; 2278 /* 2279 * Mutexes are short lived. Threads waiting on them will 2280 * hit thread_suspend_check() soon. 2281 */ 2282 } else if (p->p_state == PRS_NORMAL) { 2283 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2284 tdsigwakeup(td, sig, action, intrval); 2285 goto out; 2286 } 2287 2288 MPASS(action == SIG_DFL); 2289 2290 if (prop & SA_STOP) { 2291 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2292 goto out; 2293 p->p_flag |= P_STOPPED_SIG; 2294 p->p_xstat = sig; 2295 PROC_SLOCK(p); 2296 sig_suspend_threads(td, p, 1); 2297 if (p->p_numthreads == p->p_suspcount) { 2298 /* 2299 * only thread sending signal to another 2300 * process can reach here, if thread is sending 2301 * signal to its process, because thread does 2302 * not suspend itself here, p_numthreads 2303 * should never be equal to p_suspcount. 2304 */ 2305 thread_stopped(p); 2306 PROC_SUNLOCK(p); 2307 sigqueue_delete_proc(p, p->p_xstat); 2308 } else 2309 PROC_SUNLOCK(p); 2310 goto out; 2311 } 2312 } else { 2313 /* Not in "NORMAL" state. discard the signal. */ 2314 sigqueue_delete(sigqueue, sig); 2315 goto out; 2316 } 2317 2318 /* 2319 * The process is not stopped so we need to apply the signal to all the 2320 * running threads. 2321 */ 2322 runfast: 2323 tdsigwakeup(td, sig, action, intrval); 2324 PROC_SLOCK(p); 2325 thread_unsuspend(p); 2326 PROC_SUNLOCK(p); 2327 out: 2328 /* If we jump here, proc slock should not be owned. */ 2329 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2330 return (ret); 2331 } 2332 2333 /* 2334 * The force of a signal has been directed against a single 2335 * thread. We need to see what we can do about knocking it 2336 * out of any sleep it may be in etc. 2337 */ 2338 static void 2339 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2340 { 2341 struct proc *p = td->td_proc; 2342 register int prop; 2343 int wakeup_swapper; 2344 2345 wakeup_swapper = 0; 2346 PROC_LOCK_ASSERT(p, MA_OWNED); 2347 prop = sigprop(sig); 2348 2349 PROC_SLOCK(p); 2350 thread_lock(td); 2351 /* 2352 * Bring the priority of a thread up if we want it to get 2353 * killed in this lifetime. 2354 */ 2355 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2356 sched_prio(td, PUSER); 2357 if (TD_ON_SLEEPQ(td)) { 2358 /* 2359 * If thread is sleeping uninterruptibly 2360 * we can't interrupt the sleep... the signal will 2361 * be noticed when the process returns through 2362 * trap() or syscall(). 2363 */ 2364 if ((td->td_flags & TDF_SINTR) == 0) 2365 goto out; 2366 /* 2367 * If SIGCONT is default (or ignored) and process is 2368 * asleep, we are finished; the process should not 2369 * be awakened. 2370 */ 2371 if ((prop & SA_CONT) && action == SIG_DFL) { 2372 thread_unlock(td); 2373 PROC_SUNLOCK(p); 2374 sigqueue_delete(&p->p_sigqueue, sig); 2375 /* 2376 * It may be on either list in this state. 2377 * Remove from both for now. 2378 */ 2379 sigqueue_delete(&td->td_sigqueue, sig); 2380 return; 2381 } 2382 2383 /* 2384 * Don't awaken a sleeping thread for SIGSTOP if the 2385 * STOP signal is deferred. 2386 */ 2387 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2388 goto out; 2389 2390 /* 2391 * Give low priority threads a better chance to run. 2392 */ 2393 if (td->td_priority > PUSER) 2394 sched_prio(td, PUSER); 2395 2396 wakeup_swapper = sleepq_abort(td, intrval); 2397 } else { 2398 /* 2399 * Other states do nothing with the signal immediately, 2400 * other than kicking ourselves if we are running. 2401 * It will either never be noticed, or noticed very soon. 2402 */ 2403 #ifdef SMP 2404 if (TD_IS_RUNNING(td) && td != curthread) 2405 forward_signal(td); 2406 #endif 2407 } 2408 out: 2409 PROC_SUNLOCK(p); 2410 thread_unlock(td); 2411 if (wakeup_swapper) 2412 kick_proc0(); 2413 } 2414 2415 static void 2416 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2417 { 2418 struct thread *td2; 2419 2420 PROC_LOCK_ASSERT(p, MA_OWNED); 2421 PROC_SLOCK_ASSERT(p, MA_OWNED); 2422 2423 FOREACH_THREAD_IN_PROC(p, td2) { 2424 thread_lock(td2); 2425 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2426 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2427 (td2->td_flags & TDF_SINTR)) { 2428 if (td2->td_flags & TDF_SBDRY) { 2429 /* 2430 * Once a thread is asleep with 2431 * TDF_SBDRY set, it should never 2432 * become suspended due to this check. 2433 */ 2434 KASSERT(!TD_IS_SUSPENDED(td2), 2435 ("thread with deferred stops suspended")); 2436 } else if (!TD_IS_SUSPENDED(td2)) { 2437 thread_suspend_one(td2); 2438 } 2439 } else if (!TD_IS_SUSPENDED(td2)) { 2440 if (sending || td != td2) 2441 td2->td_flags |= TDF_ASTPENDING; 2442 #ifdef SMP 2443 if (TD_IS_RUNNING(td2) && td2 != td) 2444 forward_signal(td2); 2445 #endif 2446 } 2447 thread_unlock(td2); 2448 } 2449 } 2450 2451 int 2452 ptracestop(struct thread *td, int sig) 2453 { 2454 struct proc *p = td->td_proc; 2455 2456 PROC_LOCK_ASSERT(p, MA_OWNED); 2457 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2458 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2459 &p->p_mtx.lock_object, "Stopping for traced signal"); 2460 2461 td->td_dbgflags |= TDB_XSIG; 2462 td->td_xsig = sig; 2463 PROC_SLOCK(p); 2464 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2465 if (p->p_flag & P_SINGLE_EXIT) { 2466 td->td_dbgflags &= ~TDB_XSIG; 2467 PROC_SUNLOCK(p); 2468 return (sig); 2469 } 2470 /* 2471 * Just make wait() to work, the last stopped thread 2472 * will win. 2473 */ 2474 p->p_xstat = sig; 2475 p->p_xthread = td; 2476 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2477 sig_suspend_threads(td, p, 0); 2478 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2479 td->td_dbgflags &= ~TDB_STOPATFORK; 2480 cv_broadcast(&p->p_dbgwait); 2481 } 2482 stopme: 2483 thread_suspend_switch(td); 2484 if (p->p_xthread == td) 2485 p->p_xthread = NULL; 2486 if (!(p->p_flag & P_TRACED)) 2487 break; 2488 if (td->td_dbgflags & TDB_SUSPEND) { 2489 if (p->p_flag & P_SINGLE_EXIT) 2490 break; 2491 goto stopme; 2492 } 2493 } 2494 PROC_SUNLOCK(p); 2495 return (td->td_xsig); 2496 } 2497 2498 static void 2499 reschedule_signals(struct proc *p, sigset_t block, int flags) 2500 { 2501 struct sigacts *ps; 2502 struct thread *td; 2503 int sig; 2504 2505 PROC_LOCK_ASSERT(p, MA_OWNED); 2506 if (SIGISEMPTY(p->p_siglist)) 2507 return; 2508 ps = p->p_sigacts; 2509 SIGSETAND(block, p->p_siglist); 2510 while ((sig = sig_ffs(&block)) != 0) { 2511 SIGDELSET(block, sig); 2512 td = sigtd(p, sig, 0); 2513 signotify(td); 2514 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2515 mtx_lock(&ps->ps_mtx); 2516 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2517 tdsigwakeup(td, sig, SIG_CATCH, 2518 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2519 ERESTART)); 2520 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2521 mtx_unlock(&ps->ps_mtx); 2522 } 2523 } 2524 2525 void 2526 tdsigcleanup(struct thread *td) 2527 { 2528 struct proc *p; 2529 sigset_t unblocked; 2530 2531 p = td->td_proc; 2532 PROC_LOCK_ASSERT(p, MA_OWNED); 2533 2534 sigqueue_flush(&td->td_sigqueue); 2535 if (p->p_numthreads == 1) 2536 return; 2537 2538 /* 2539 * Since we cannot handle signals, notify signal post code 2540 * about this by filling the sigmask. 2541 * 2542 * Also, if needed, wake up thread(s) that do not block the 2543 * same signals as the exiting thread, since the thread might 2544 * have been selected for delivery and woken up. 2545 */ 2546 SIGFILLSET(unblocked); 2547 SIGSETNAND(unblocked, td->td_sigmask); 2548 SIGFILLSET(td->td_sigmask); 2549 reschedule_signals(p, unblocked, 0); 2550 2551 } 2552 2553 /* 2554 * Defer the delivery of SIGSTOP for the current thread. Returns true 2555 * if stops were deferred and false if they were already deferred. 2556 */ 2557 int 2558 sigdeferstop(void) 2559 { 2560 struct thread *td; 2561 2562 td = curthread; 2563 if (td->td_flags & TDF_SBDRY) 2564 return (0); 2565 thread_lock(td); 2566 td->td_flags |= TDF_SBDRY; 2567 thread_unlock(td); 2568 return (1); 2569 } 2570 2571 /* 2572 * Permit the delivery of SIGSTOP for the current thread. This does 2573 * not immediately suspend if a stop was posted. Instead, the thread 2574 * will suspend either via ast() or a subsequent interruptible sleep. 2575 */ 2576 void 2577 sigallowstop() 2578 { 2579 struct thread *td; 2580 2581 td = curthread; 2582 thread_lock(td); 2583 td->td_flags &= ~TDF_SBDRY; 2584 thread_unlock(td); 2585 } 2586 2587 /* 2588 * If the current process has received a signal (should be caught or cause 2589 * termination, should interrupt current syscall), return the signal number. 2590 * Stop signals with default action are processed immediately, then cleared; 2591 * they aren't returned. This is checked after each entry to the system for 2592 * a syscall or trap (though this can usually be done without calling issignal 2593 * by checking the pending signal masks in cursig.) The normal call 2594 * sequence is 2595 * 2596 * while (sig = cursig(curthread)) 2597 * postsig(sig); 2598 */ 2599 static int 2600 issignal(struct thread *td) 2601 { 2602 struct proc *p; 2603 struct sigacts *ps; 2604 struct sigqueue *queue; 2605 sigset_t sigpending; 2606 int sig, prop, newsig; 2607 2608 p = td->td_proc; 2609 ps = p->p_sigacts; 2610 mtx_assert(&ps->ps_mtx, MA_OWNED); 2611 PROC_LOCK_ASSERT(p, MA_OWNED); 2612 for (;;) { 2613 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2614 2615 sigpending = td->td_sigqueue.sq_signals; 2616 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2617 SIGSETNAND(sigpending, td->td_sigmask); 2618 2619 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2620 SIG_STOPSIGMASK(sigpending); 2621 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2622 return (0); 2623 sig = sig_ffs(&sigpending); 2624 2625 if (p->p_stops & S_SIG) { 2626 mtx_unlock(&ps->ps_mtx); 2627 stopevent(p, S_SIG, sig); 2628 mtx_lock(&ps->ps_mtx); 2629 } 2630 2631 /* 2632 * We should see pending but ignored signals 2633 * only if P_TRACED was on when they were posted. 2634 */ 2635 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2636 sigqueue_delete(&td->td_sigqueue, sig); 2637 sigqueue_delete(&p->p_sigqueue, sig); 2638 continue; 2639 } 2640 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) { 2641 /* 2642 * If traced, always stop. 2643 * Remove old signal from queue before the stop. 2644 * XXX shrug off debugger, it causes siginfo to 2645 * be thrown away. 2646 */ 2647 queue = &td->td_sigqueue; 2648 td->td_dbgksi.ksi_signo = 0; 2649 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2650 queue = &p->p_sigqueue; 2651 sigqueue_get(queue, sig, &td->td_dbgksi); 2652 } 2653 2654 mtx_unlock(&ps->ps_mtx); 2655 newsig = ptracestop(td, sig); 2656 mtx_lock(&ps->ps_mtx); 2657 2658 if (sig != newsig) { 2659 2660 /* 2661 * If parent wants us to take the signal, 2662 * then it will leave it in p->p_xstat; 2663 * otherwise we just look for signals again. 2664 */ 2665 if (newsig == 0) 2666 continue; 2667 sig = newsig; 2668 2669 /* 2670 * Put the new signal into td_sigqueue. If the 2671 * signal is being masked, look for other 2672 * signals. 2673 */ 2674 sigqueue_add(queue, sig, NULL); 2675 if (SIGISMEMBER(td->td_sigmask, sig)) 2676 continue; 2677 signotify(td); 2678 } else { 2679 if (td->td_dbgksi.ksi_signo != 0) { 2680 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2681 if (sigqueue_add(&td->td_sigqueue, sig, 2682 &td->td_dbgksi) != 0) 2683 td->td_dbgksi.ksi_signo = 0; 2684 } 2685 if (td->td_dbgksi.ksi_signo == 0) 2686 sigqueue_add(&td->td_sigqueue, sig, 2687 NULL); 2688 } 2689 2690 /* 2691 * If the traced bit got turned off, go back up 2692 * to the top to rescan signals. This ensures 2693 * that p_sig* and p_sigact are consistent. 2694 */ 2695 if ((p->p_flag & P_TRACED) == 0) 2696 continue; 2697 } 2698 2699 prop = sigprop(sig); 2700 2701 /* 2702 * Decide whether the signal should be returned. 2703 * Return the signal's number, or fall through 2704 * to clear it from the pending mask. 2705 */ 2706 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2707 2708 case (intptr_t)SIG_DFL: 2709 /* 2710 * Don't take default actions on system processes. 2711 */ 2712 if (p->p_pid <= 1) { 2713 #ifdef DIAGNOSTIC 2714 /* 2715 * Are you sure you want to ignore SIGSEGV 2716 * in init? XXX 2717 */ 2718 printf("Process (pid %lu) got signal %d\n", 2719 (u_long)p->p_pid, sig); 2720 #endif 2721 break; /* == ignore */ 2722 } 2723 /* 2724 * If there is a pending stop signal to process 2725 * with default action, stop here, 2726 * then clear the signal. However, 2727 * if process is member of an orphaned 2728 * process group, ignore tty stop signals. 2729 */ 2730 if (prop & SA_STOP) { 2731 if (p->p_flag & (P_TRACED|P_WEXIT) || 2732 (p->p_pgrp->pg_jobc == 0 && 2733 prop & SA_TTYSTOP)) 2734 break; /* == ignore */ 2735 mtx_unlock(&ps->ps_mtx); 2736 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2737 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2738 p->p_flag |= P_STOPPED_SIG; 2739 p->p_xstat = sig; 2740 PROC_SLOCK(p); 2741 sig_suspend_threads(td, p, 0); 2742 thread_suspend_switch(td); 2743 PROC_SUNLOCK(p); 2744 mtx_lock(&ps->ps_mtx); 2745 break; 2746 } else if (prop & SA_IGNORE) { 2747 /* 2748 * Except for SIGCONT, shouldn't get here. 2749 * Default action is to ignore; drop it. 2750 */ 2751 break; /* == ignore */ 2752 } else 2753 return (sig); 2754 /*NOTREACHED*/ 2755 2756 case (intptr_t)SIG_IGN: 2757 /* 2758 * Masking above should prevent us ever trying 2759 * to take action on an ignored signal other 2760 * than SIGCONT, unless process is traced. 2761 */ 2762 if ((prop & SA_CONT) == 0 && 2763 (p->p_flag & P_TRACED) == 0) 2764 printf("issignal\n"); 2765 break; /* == ignore */ 2766 2767 default: 2768 /* 2769 * This signal has an action, let 2770 * postsig() process it. 2771 */ 2772 return (sig); 2773 } 2774 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2775 sigqueue_delete(&p->p_sigqueue, sig); 2776 } 2777 /* NOTREACHED */ 2778 } 2779 2780 void 2781 thread_stopped(struct proc *p) 2782 { 2783 int n; 2784 2785 PROC_LOCK_ASSERT(p, MA_OWNED); 2786 PROC_SLOCK_ASSERT(p, MA_OWNED); 2787 n = p->p_suspcount; 2788 if (p == curproc) 2789 n++; 2790 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2791 PROC_SUNLOCK(p); 2792 p->p_flag &= ~P_WAITED; 2793 PROC_LOCK(p->p_pptr); 2794 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2795 CLD_TRAPPED : CLD_STOPPED); 2796 PROC_UNLOCK(p->p_pptr); 2797 PROC_SLOCK(p); 2798 } 2799 } 2800 2801 /* 2802 * Take the action for the specified signal 2803 * from the current set of pending signals. 2804 */ 2805 int 2806 postsig(sig) 2807 register int sig; 2808 { 2809 struct thread *td = curthread; 2810 register struct proc *p = td->td_proc; 2811 struct sigacts *ps; 2812 sig_t action; 2813 ksiginfo_t ksi; 2814 sigset_t returnmask, mask; 2815 2816 KASSERT(sig != 0, ("postsig")); 2817 2818 PROC_LOCK_ASSERT(p, MA_OWNED); 2819 ps = p->p_sigacts; 2820 mtx_assert(&ps->ps_mtx, MA_OWNED); 2821 ksiginfo_init(&ksi); 2822 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2823 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2824 return (0); 2825 ksi.ksi_signo = sig; 2826 if (ksi.ksi_code == SI_TIMER) 2827 itimer_accept(p, ksi.ksi_timerid, &ksi); 2828 action = ps->ps_sigact[_SIG_IDX(sig)]; 2829 #ifdef KTRACE 2830 if (KTRPOINT(td, KTR_PSIG)) 2831 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2832 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2833 #endif 2834 if (p->p_stops & S_SIG) { 2835 mtx_unlock(&ps->ps_mtx); 2836 stopevent(p, S_SIG, sig); 2837 mtx_lock(&ps->ps_mtx); 2838 } 2839 2840 if (action == SIG_DFL) { 2841 /* 2842 * Default action, where the default is to kill 2843 * the process. (Other cases were ignored above.) 2844 */ 2845 mtx_unlock(&ps->ps_mtx); 2846 sigexit(td, sig); 2847 /* NOTREACHED */ 2848 } else { 2849 /* 2850 * If we get here, the signal must be caught. 2851 */ 2852 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2853 ("postsig action")); 2854 /* 2855 * Set the new mask value and also defer further 2856 * occurrences of this signal. 2857 * 2858 * Special case: user has done a sigsuspend. Here the 2859 * current mask is not of interest, but rather the 2860 * mask from before the sigsuspend is what we want 2861 * restored after the signal processing is completed. 2862 */ 2863 if (td->td_pflags & TDP_OLDMASK) { 2864 returnmask = td->td_oldsigmask; 2865 td->td_pflags &= ~TDP_OLDMASK; 2866 } else 2867 returnmask = td->td_sigmask; 2868 2869 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2870 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2871 SIGADDSET(mask, sig); 2872 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2873 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2874 2875 if (SIGISMEMBER(ps->ps_sigreset, sig)) 2876 sigdflt(ps, sig); 2877 td->td_ru.ru_nsignals++; 2878 if (p->p_sig == sig) { 2879 p->p_code = 0; 2880 p->p_sig = 0; 2881 } 2882 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2883 } 2884 return (1); 2885 } 2886 2887 /* 2888 * Kill the current process for stated reason. 2889 */ 2890 void 2891 killproc(p, why) 2892 struct proc *p; 2893 char *why; 2894 { 2895 2896 PROC_LOCK_ASSERT(p, MA_OWNED); 2897 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 2898 p->p_comm); 2899 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 2900 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2901 p->p_flag |= P_WKILLED; 2902 kern_psignal(p, SIGKILL); 2903 } 2904 2905 /* 2906 * Force the current process to exit with the specified signal, dumping core 2907 * if appropriate. We bypass the normal tests for masked and caught signals, 2908 * allowing unrecoverable failures to terminate the process without changing 2909 * signal state. Mark the accounting record with the signal termination. 2910 * If dumping core, save the signal number for the debugger. Calls exit and 2911 * does not return. 2912 */ 2913 void 2914 sigexit(td, sig) 2915 struct thread *td; 2916 int sig; 2917 { 2918 struct proc *p = td->td_proc; 2919 2920 PROC_LOCK_ASSERT(p, MA_OWNED); 2921 p->p_acflag |= AXSIG; 2922 /* 2923 * We must be single-threading to generate a core dump. This 2924 * ensures that the registers in the core file are up-to-date. 2925 * Also, the ELF dump handler assumes that the thread list doesn't 2926 * change out from under it. 2927 * 2928 * XXX If another thread attempts to single-thread before us 2929 * (e.g. via fork()), we won't get a dump at all. 2930 */ 2931 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2932 p->p_sig = sig; 2933 /* 2934 * Log signals which would cause core dumps 2935 * (Log as LOG_INFO to appease those who don't want 2936 * these messages.) 2937 * XXX : Todo, as well as euid, write out ruid too 2938 * Note that coredump() drops proc lock. 2939 */ 2940 if (coredump(td) == 0) 2941 sig |= WCOREFLAG; 2942 if (kern_logsigexit) 2943 log(LOG_INFO, 2944 "pid %d (%s), uid %d: exited on signal %d%s\n", 2945 p->p_pid, p->p_comm, 2946 td->td_ucred ? td->td_ucred->cr_uid : -1, 2947 sig &~ WCOREFLAG, 2948 sig & WCOREFLAG ? " (core dumped)" : ""); 2949 } else 2950 PROC_UNLOCK(p); 2951 exit1(td, W_EXITCODE(0, sig)); 2952 /* NOTREACHED */ 2953 } 2954 2955 /* 2956 * Send queued SIGCHLD to parent when child process's state 2957 * is changed. 2958 */ 2959 static void 2960 sigparent(struct proc *p, int reason, int status) 2961 { 2962 PROC_LOCK_ASSERT(p, MA_OWNED); 2963 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2964 2965 if (p->p_ksi != NULL) { 2966 p->p_ksi->ksi_signo = SIGCHLD; 2967 p->p_ksi->ksi_code = reason; 2968 p->p_ksi->ksi_status = status; 2969 p->p_ksi->ksi_pid = p->p_pid; 2970 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2971 if (KSI_ONQ(p->p_ksi)) 2972 return; 2973 } 2974 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2975 } 2976 2977 static void 2978 childproc_jobstate(struct proc *p, int reason, int sig) 2979 { 2980 struct sigacts *ps; 2981 2982 PROC_LOCK_ASSERT(p, MA_OWNED); 2983 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2984 2985 /* 2986 * Wake up parent sleeping in kern_wait(), also send 2987 * SIGCHLD to parent, but SIGCHLD does not guarantee 2988 * that parent will awake, because parent may masked 2989 * the signal. 2990 */ 2991 p->p_pptr->p_flag |= P_STATCHILD; 2992 wakeup(p->p_pptr); 2993 2994 ps = p->p_pptr->p_sigacts; 2995 mtx_lock(&ps->ps_mtx); 2996 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2997 mtx_unlock(&ps->ps_mtx); 2998 sigparent(p, reason, sig); 2999 } else 3000 mtx_unlock(&ps->ps_mtx); 3001 } 3002 3003 void 3004 childproc_stopped(struct proc *p, int reason) 3005 { 3006 /* p_xstat is a plain signal number, not a full wait() status here. */ 3007 childproc_jobstate(p, reason, p->p_xstat); 3008 } 3009 3010 void 3011 childproc_continued(struct proc *p) 3012 { 3013 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3014 } 3015 3016 void 3017 childproc_exited(struct proc *p) 3018 { 3019 int reason; 3020 int xstat = p->p_xstat; /* convert to int */ 3021 int status; 3022 3023 if (WCOREDUMP(xstat)) 3024 reason = CLD_DUMPED, status = WTERMSIG(xstat); 3025 else if (WIFSIGNALED(xstat)) 3026 reason = CLD_KILLED, status = WTERMSIG(xstat); 3027 else 3028 reason = CLD_EXITED, status = WEXITSTATUS(xstat); 3029 /* 3030 * XXX avoid calling wakeup(p->p_pptr), the work is 3031 * done in exit1(). 3032 */ 3033 sigparent(p, reason, status); 3034 } 3035 3036 /* 3037 * We only have 1 character for the core count in the format 3038 * string, so the range will be 0-9 3039 */ 3040 #define MAX_NUM_CORES 10 3041 static int num_cores = 5; 3042 3043 static int 3044 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3045 { 3046 int error; 3047 int new_val; 3048 3049 new_val = num_cores; 3050 error = sysctl_handle_int(oidp, &new_val, 0, req); 3051 if (error != 0 || req->newptr == NULL) 3052 return (error); 3053 if (new_val > MAX_NUM_CORES) 3054 new_val = MAX_NUM_CORES; 3055 if (new_val < 0) 3056 new_val = 0; 3057 num_cores = new_val; 3058 return (0); 3059 } 3060 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3061 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3062 3063 #if defined(COMPRESS_USER_CORES) 3064 int compress_user_cores = 1; 3065 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 3066 &compress_user_cores, 0, "Compression of user corefiles"); 3067 3068 int compress_user_cores_gzlevel = -1; /* default level */ 3069 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 3070 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level"); 3071 3072 #define GZ_SUFFIX ".gz" 3073 #define GZ_SUFFIX_LEN 3 3074 #endif 3075 3076 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3077 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3078 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3079 sizeof(corefilename), "Process corefile name format string"); 3080 3081 /* 3082 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3083 * Expand the name described in corefilename, using name, uid, and pid 3084 * and open/create core file. 3085 * corefilename is a printf-like string, with three format specifiers: 3086 * %N name of process ("name") 3087 * %P process id (pid) 3088 * %U user id (uid) 3089 * For example, "%N.core" is the default; they can be disabled completely 3090 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3091 * This is controlled by the sysctl variable kern.corefile (see above). 3092 */ 3093 static int 3094 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3095 int compress, struct vnode **vpp, char **namep) 3096 { 3097 struct nameidata nd; 3098 struct sbuf sb; 3099 const char *format; 3100 char *hostname, *name; 3101 int indexpos, i, error, cmode, flags, oflags; 3102 3103 hostname = NULL; 3104 format = corefilename; 3105 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3106 indexpos = -1; 3107 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3108 for (i = 0; format[i] != '\0'; i++) { 3109 switch (format[i]) { 3110 case '%': /* Format character */ 3111 i++; 3112 switch (format[i]) { 3113 case '%': 3114 sbuf_putc(&sb, '%'); 3115 break; 3116 case 'H': /* hostname */ 3117 if (hostname == NULL) { 3118 hostname = malloc(MAXHOSTNAMELEN, 3119 M_TEMP, M_WAITOK); 3120 } 3121 getcredhostname(td->td_ucred, hostname, 3122 MAXHOSTNAMELEN); 3123 sbuf_printf(&sb, "%s", hostname); 3124 break; 3125 case 'I': /* autoincrementing index */ 3126 sbuf_printf(&sb, ""); 3127 indexpos = sbuf_len(&sb) - 1; 3128 break; 3129 case 'N': /* process name */ 3130 sbuf_printf(&sb, "%s", comm); 3131 break; 3132 case 'P': /* process id */ 3133 sbuf_printf(&sb, "%u", pid); 3134 break; 3135 case 'U': /* user id */ 3136 sbuf_printf(&sb, "%u", uid); 3137 break; 3138 default: 3139 log(LOG_ERR, 3140 "Unknown format character %c in " 3141 "corename `%s'\n", format[i], format); 3142 break; 3143 } 3144 break; 3145 default: 3146 sbuf_putc(&sb, format[i]); 3147 break; 3148 } 3149 } 3150 free(hostname, M_TEMP); 3151 #ifdef COMPRESS_USER_CORES 3152 if (compress) 3153 sbuf_printf(&sb, GZ_SUFFIX); 3154 #endif 3155 if (sbuf_error(&sb) != 0) { 3156 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3157 "long\n", (long)pid, comm, (u_long)uid); 3158 sbuf_delete(&sb); 3159 free(name, M_TEMP); 3160 return (ENOMEM); 3161 } 3162 sbuf_finish(&sb); 3163 sbuf_delete(&sb); 3164 3165 cmode = S_IRUSR | S_IWUSR; 3166 oflags = VN_OPEN_NOAUDIT | (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3167 3168 /* 3169 * If the core format has a %I in it, then we need to check 3170 * for existing corefiles before returning a name. 3171 * To do this we iterate over 0..num_cores to find a 3172 * non-existing core file name to use. 3173 */ 3174 if (indexpos != -1) { 3175 for (i = 0; i < num_cores; i++) { 3176 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3177 name[indexpos] = '' + i; 3178 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3179 error = vn_open_cred(&nd, &flags, cmode, oflags, 3180 td->td_ucred, NULL); 3181 if (error) { 3182 if (error == EEXIST) 3183 continue; 3184 log(LOG_ERR, 3185 "pid %d (%s), uid (%u): Path `%s' failed " 3186 "on initial open test, error = %d\n", 3187 pid, comm, uid, name, error); 3188 } 3189 goto out; 3190 } 3191 } 3192 3193 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3194 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3195 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3196 out: 3197 if (error) { 3198 #ifdef AUDIT 3199 audit_proc_coredump(td, name, error); 3200 #endif 3201 free(name, M_TEMP); 3202 return (error); 3203 } 3204 NDFREE(&nd, NDF_ONLY_PNBUF); 3205 *vpp = nd.ni_vp; 3206 *namep = name; 3207 return (0); 3208 } 3209 3210 /* 3211 * Dump a process' core. The main routine does some 3212 * policy checking, and creates the name of the coredump; 3213 * then it passes on a vnode and a size limit to the process-specific 3214 * coredump routine if there is one; if there _is not_ one, it returns 3215 * ENOSYS; otherwise it returns the error from the process-specific routine. 3216 */ 3217 3218 static int 3219 coredump(struct thread *td) 3220 { 3221 struct proc *p = td->td_proc; 3222 struct ucred *cred = td->td_ucred; 3223 struct vnode *vp; 3224 struct flock lf; 3225 struct vattr vattr; 3226 int error, error1, locked; 3227 struct mount *mp; 3228 char *name; /* name of corefile */ 3229 off_t limit; 3230 int compress; 3231 3232 #ifdef COMPRESS_USER_CORES 3233 compress = compress_user_cores; 3234 #else 3235 compress = 0; 3236 #endif 3237 PROC_LOCK_ASSERT(p, MA_OWNED); 3238 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3239 _STOPEVENT(p, S_CORE, 0); 3240 3241 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0)) { 3242 PROC_UNLOCK(p); 3243 return (EFAULT); 3244 } 3245 3246 /* 3247 * Note that the bulk of limit checking is done after 3248 * the corefile is created. The exception is if the limit 3249 * for corefiles is 0, in which case we don't bother 3250 * creating the corefile at all. This layout means that 3251 * a corefile is truncated instead of not being created, 3252 * if it is larger than the limit. 3253 */ 3254 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3255 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3256 PROC_UNLOCK(p); 3257 return (EFBIG); 3258 } 3259 PROC_UNLOCK(p); 3260 3261 restart: 3262 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress, 3263 &vp, &name); 3264 if (error != 0) 3265 return (error); 3266 3267 /* Don't dump to non-regular files or files with links. */ 3268 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3269 vattr.va_nlink != 1) { 3270 VOP_UNLOCK(vp, 0); 3271 error = EFAULT; 3272 goto close; 3273 } 3274 3275 VOP_UNLOCK(vp, 0); 3276 lf.l_whence = SEEK_SET; 3277 lf.l_start = 0; 3278 lf.l_len = 0; 3279 lf.l_type = F_WRLCK; 3280 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3281 3282 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3283 lf.l_type = F_UNLCK; 3284 if (locked) 3285 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3286 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3287 goto out; 3288 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3289 goto out; 3290 free(name, M_TEMP); 3291 goto restart; 3292 } 3293 3294 VATTR_NULL(&vattr); 3295 vattr.va_size = 0; 3296 if (set_core_nodump_flag) 3297 vattr.va_flags = UF_NODUMP; 3298 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3299 VOP_SETATTR(vp, &vattr, cred); 3300 VOP_UNLOCK(vp, 0); 3301 vn_finished_write(mp); 3302 PROC_LOCK(p); 3303 p->p_acflag |= ACORE; 3304 PROC_UNLOCK(p); 3305 3306 if (p->p_sysent->sv_coredump != NULL) { 3307 error = p->p_sysent->sv_coredump(td, vp, limit, 3308 compress ? IMGACT_CORE_COMPRESS : 0); 3309 } else { 3310 error = ENOSYS; 3311 } 3312 3313 if (locked) { 3314 lf.l_type = F_UNLCK; 3315 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3316 } 3317 close: 3318 error1 = vn_close(vp, FWRITE, cred, td); 3319 if (error == 0) 3320 error = error1; 3321 out: 3322 #ifdef AUDIT 3323 audit_proc_coredump(td, name, error); 3324 #endif 3325 free(name, M_TEMP); 3326 return (error); 3327 } 3328 3329 /* 3330 * Nonexistent system call-- signal process (may want to handle it). Flag 3331 * error in case process won't see signal immediately (blocked or ignored). 3332 */ 3333 #ifndef _SYS_SYSPROTO_H_ 3334 struct nosys_args { 3335 int dummy; 3336 }; 3337 #endif 3338 /* ARGSUSED */ 3339 int 3340 nosys(td, args) 3341 struct thread *td; 3342 struct nosys_args *args; 3343 { 3344 struct proc *p = td->td_proc; 3345 3346 PROC_LOCK(p); 3347 tdsignal(td, SIGSYS); 3348 PROC_UNLOCK(p); 3349 return (ENOSYS); 3350 } 3351 3352 /* 3353 * Send a SIGIO or SIGURG signal to a process or process group using stored 3354 * credentials rather than those of the current process. 3355 */ 3356 void 3357 pgsigio(sigiop, sig, checkctty) 3358 struct sigio **sigiop; 3359 int sig, checkctty; 3360 { 3361 ksiginfo_t ksi; 3362 struct sigio *sigio; 3363 3364 ksiginfo_init(&ksi); 3365 ksi.ksi_signo = sig; 3366 ksi.ksi_code = SI_KERNEL; 3367 3368 SIGIO_LOCK(); 3369 sigio = *sigiop; 3370 if (sigio == NULL) { 3371 SIGIO_UNLOCK(); 3372 return; 3373 } 3374 if (sigio->sio_pgid > 0) { 3375 PROC_LOCK(sigio->sio_proc); 3376 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3377 kern_psignal(sigio->sio_proc, sig); 3378 PROC_UNLOCK(sigio->sio_proc); 3379 } else if (sigio->sio_pgid < 0) { 3380 struct proc *p; 3381 3382 PGRP_LOCK(sigio->sio_pgrp); 3383 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3384 PROC_LOCK(p); 3385 if (p->p_state == PRS_NORMAL && 3386 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3387 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3388 kern_psignal(p, sig); 3389 PROC_UNLOCK(p); 3390 } 3391 PGRP_UNLOCK(sigio->sio_pgrp); 3392 } 3393 SIGIO_UNLOCK(); 3394 } 3395 3396 static int 3397 filt_sigattach(struct knote *kn) 3398 { 3399 struct proc *p = curproc; 3400 3401 kn->kn_ptr.p_proc = p; 3402 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3403 3404 knlist_add(&p->p_klist, kn, 0); 3405 3406 return (0); 3407 } 3408 3409 static void 3410 filt_sigdetach(struct knote *kn) 3411 { 3412 struct proc *p = kn->kn_ptr.p_proc; 3413 3414 knlist_remove(&p->p_klist, kn, 0); 3415 } 3416 3417 /* 3418 * signal knotes are shared with proc knotes, so we apply a mask to 3419 * the hint in order to differentiate them from process hints. This 3420 * could be avoided by using a signal-specific knote list, but probably 3421 * isn't worth the trouble. 3422 */ 3423 static int 3424 filt_signal(struct knote *kn, long hint) 3425 { 3426 3427 if (hint & NOTE_SIGNAL) { 3428 hint &= ~NOTE_SIGNAL; 3429 3430 if (kn->kn_id == hint) 3431 kn->kn_data++; 3432 } 3433 return (kn->kn_data != 0); 3434 } 3435 3436 struct sigacts * 3437 sigacts_alloc(void) 3438 { 3439 struct sigacts *ps; 3440 3441 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3442 ps->ps_refcnt = 1; 3443 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3444 return (ps); 3445 } 3446 3447 void 3448 sigacts_free(struct sigacts *ps) 3449 { 3450 3451 if (refcount_release(&ps->ps_refcnt) == 0) 3452 return; 3453 mtx_destroy(&ps->ps_mtx); 3454 free(ps, M_SUBPROC); 3455 } 3456 3457 struct sigacts * 3458 sigacts_hold(struct sigacts *ps) 3459 { 3460 3461 refcount_acquire(&ps->ps_refcnt); 3462 return (ps); 3463 } 3464 3465 void 3466 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3467 { 3468 3469 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3470 mtx_lock(&src->ps_mtx); 3471 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3472 mtx_unlock(&src->ps_mtx); 3473 } 3474 3475 int 3476 sigacts_shared(struct sigacts *ps) 3477 { 3478 3479 return (ps->ps_refcnt > 1); 3480 }
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